The invention provides a hologram-recorded article with a wavelength multiplex volume phase type of hologram recorded thereon which has been treated to widen a bandwidth of diffracted wavelength.

The invention provides a reflection type color display device comprising a transmission type spatial light modulator (36) comprising a collection of pixels (36') and having a controllable transmittance per pixel, and a reflection type hologram color filter (30) located on a back side of said modulator. The modulator preferably comprises a liquid crystal display element.

The invention provides a hologram-replicating method, a hologram-making method using the same, and a hologram-recorded article. A hologram-recording subject plate comprises a transparent solid block and a hologram-recording subject contained therein. A photosensitive material film is applied directly onto one surface of the subject plate, and the subject plate is then irradiated with laser light through the photosensitive material film. Such simple operation enables a multiplicity of identical holograms to be recorded in an easy, stable yet continuous manner.

A holographic recording medium in which information can be reproduced by phase conjugate beam without requiring a mirror for obtaining the phase conjugate beam and its driving part and recording density is not reduced. The recording medium includes a recording layer in which an interference pattern is recorded and a light absorption/transmission layer which can be reversibly changed to be in a first state where signal beam and reference beam passed through the recording layer are absorbed at the time of recording of information and a second state where the reference beam is transmitted at the time of reproduction of information, and the reference beam transmitted through the light absorption/transmission layer is reflected by a reflection layer to produce the phase conjugate beam.

The invention provides a diffusing plate with the angle of diffusion controllable within a desired range by use of a hologram, which is capable of presenting bright displays so that it is applicable to, for instance, a backlighting diffusing plate for liquid crystal display device. A diffusing plate 2 having an angle of diffusion θ is brought into close contact with a hologram photosensitive material 1. Then, parallel light 3 is obliquely at an angle of incidence α on the photosensitive material while parallel light 4 is vertically incident on the diffusing plate 2. Thereupon, parallel light 4 is converted into diffused light 5 having an angle of diffraction θ upon passing through the diffusing plate 2. Diffused light 5 interferes with obliquely incident parallel light 3 from the opposite direction in photosensitive material 1 to produce interference fringes, thereby forming a reflection type hologram. Upon parallel illumination light on the hologram at the same angle of incidence α at which parallel light 3 strikes for recording, diffused light having the same angle of diffraction θ as that of diffused light 5 used for recording is reflected, and diffracted from this reflection type hologram.

The present invention provides a hologram recording method which enables obtaining floating and high-quality images which can be stereoscopically viewed from wide viewing angles of 360° in a low-cost and simple production method and to provide a hologram recording apparatus and a hologram recording medium.

Thus, the present invention relates to a hologram recording method which includes irradiating a coherent object beam virtually simultaneously to almost all the surface of a recording object to make the reflected object beam from the surface incident on a photosensitive surface of a photosensitive material, making a coherent reference beam incident on the opposite surface of the photosensitive material with respect to the photosensitive surface to generate interference fringes by the object beam and the reference beam, and recording the interference fringes on the photosensitive material, and a hologram recording medium and a hologram recording apparatus using the method.

The invention provides a diffusing plate with the angle of diffusion controllable within a desired range by use of a hologram, which is capable of presenting bright displays so that it is applicable to, for instance, a backlighting diffusing plate for liquid crystal display device. A diffusing plate 2 having an angle of diffusion θ is brought into close contact with a hologram photosensitive material 1. Then, parallel light 3 is obliquely at an angle of incidence α on the photosensitive material 1 while parallel light 4 is vertically incident on the diffusing plate 2. Thereupon, parallel light 4 is converted into diffused light 5 having an angle of diffraction θ upon passing through the diffusing plate 2. Diffused light 5 interferes with obliquely incident parallel light 3 from the opposite direction in photosensitive material 1 to produce interference fringes, thereby forming a reflection type hologram. Upon parallel illumination light on the hologram at the same angle of incidence α at which parallel light 3 strikes for recording, diffused light having the same angle of diffraction θ as that of diffused light 5 used for recording is reflected, and diffracted from this reflection type hologram.

The invention provides a hologram-recording subject plate comprising a block and a variety of subjects fixedly contained therein, which ensures easy, stable yet continuous recording of a multiplicity of identical holograms or different holograms reconstructible by illuminating light as is the case with a hologram-replicating method, a hologram-making method using the same, and a hologram-recorded article. The subject plate comprises a transparent solid block 5 and a hologram-recording subject S contained therein. A photosensitive material film 1 is applied directly onto one surface of the subject plate, and the subject plate is then irradiated with laser light 7 through the photosensitive material film 1. Such simple operation enables a multiplicity of identical holograms to be recorded in an easy, stable yet continuous manner.

The invention provides a hologram-recording subject plate comprising a block and a variety of subjects fixedly contained therein, which ensures easy, stable yet continuous recording of a multiplicity of identical holograms or different holograms reconstructible by illuminating light as is the case with a hologram-replicating method, a hologram-making method using the same, and a hologram-recorded article. The subject plate comprises a transparent solid block 5 and a hologram-recording subject S contained therein. A photosensitive material film 1 is applied directly onto one surface of the subject plate, and the subject plate is then irradiated with laser light 7 through the photosensitive material film 1. Such simple operation enables a multiplicity of identical holograms to be recorded in an easy, stable yet continuous manner.

A hologram exposure system that includes a spherically curved mirror surface (17) positioned adjacent a substrate/hologram assembly (20) that includes a spherically curved hologram recording layer supported by a spherically curved substrate surface, wherein the spherically curved mirror surface is concentric with the spherically curved substrate surface. A first rotating means (11) provides for rotation of the curved mirror surface about a first axis (X) that passes through (a) the center of curvature of the spherically curved substrate surface that supports the hologram recording layer, and (b) a point on the hologram recording layer that allows for convenient rotation about the first axis; and a second rotating means (15) provides for rotation of the curved mirror surface about a second axis (2) that is orthogonal to the first axis and intersects the first axis at the center of curvature of the substrate surface that supports the hologram recording layer. The desired hologram area of the recording layer is holographically exposed by controllably rotating the mirror/recording layer/substrate assembly about the first and second axes while illuminating the assembly with an exposure beam (EB) that is incident on the recording layer at the intersection of the recording layer with said first axis and passes through the recording layer to be reflected by said mirror surface.