Patent ID: 8956786
Filing Date: 2015-02-17
Classification: G03H

Abstract:
1. A volume hologram medium, wherein a hologram of an image of a three-dimensional object and a hologram of an image of a plane pattern are multi-recorded in a reflection hologram form by interference of reference light beams having same angle of incidence and same wavelength with a first and second object light beams having mutually different angles of incidence wherein the hologram of said image of the plane pattern is selectively recorded in only an area corresponding to said plane pattern and as a hologram comprising parallel interference fringes in the area at an angle with respect to at least a recording plane wherein the image of the three-dimensional pattern is reconstructed in one color at a replay angle approximately the same as the reference light beam as during recording of the hologram of the image; wherein the hologram of the image of the plane pattern is reconstructed at an angle of incidence corresponding to a white illumination light and in different colors depending on the angle of incidence, wherein said area includes a normal to said recording plane, said hologram of said image of the plane pattern is recorded in such an angle relation that second object light and reference light are incident on said recording plane at substantially identical angles of incidence with respect to said normal to said recording plane from mutually opposite directions between said recording plane is, and a hologram of said image of a three-dimensional object is recorded in such an angle relation that a center light ray of said first object light is substantially vertically incident on said recording plane wherein the hologram of said image of the plane pattern is reconstructed at varying angles of incidence of the white illumination light in a color having a wavelength longer that than recording wavelength depending on angles of incidence, wherein the hologram of said image of the plane pattern is reconstructed at varying angles of incidence of the white illumination light with a peak value of 100% even when replayed at a conditions different from the hologram-recording conditions, wherein the hologram of the image of the plane pattern comprises interference fringes that are mutually parallel and uniform in said area at a slant angle parallel to the ½ angle between the second object light and the reference light in a hologram photosensitive material wherein the hologram of the plane pattern image is recorded by interference of the second object and the light and reference light crossing at right angles in said area via a one-dimensional diffusion plate and wherein the hologram of the image of the plane pattern is viewable at the same wavelength over a viewing angle (α) oriented in a direction to orthogonal to the recording plane wherein the angle of incidence (θ) and an angle of diffraction (θ′) range from +45 degrees to −55 degrees.