Abstract: A light-collecting device is provided, a light-collecting device, including: a first volume hologram recorded in a hologram recording layer by interference of a first spherical wave and a planar wave, the first spherical wave passing through a light path of diffused light which radiates from a light incident point, passes through the hologram recording layer and spreads to a predetermined diameter; and a second volume hologram recorded in the hologram recording layer by interference of a second spherical wave and the planar wave, the second spherical wave passing through a light path of converging light which radiates from the same side as the first spherical wave, passes through the hologram recording layer and converges at an image-forming point distanced from the hologram recording layer by a predetermined distance, the planar wave intersecting with the first spherical wave and the second spherical wave.

Abstract: A two-dimensional coding method includes: using a two-dimensional image containing plural reference pixels each having a different brightness and data pixels representing data in accordance with brightness; and coding a binary sequence of plural bits to be recorded as a hologram by matching the brightness level of the data pixel based on the brightnesses of the plural reference pixels.

Abstract: There is provided a hologram recording method, including generating a signal light which is spatially modulated such that digital data is represented by an image of intensity distribution, irradiating the signal light on an optical recording medium after a Fourier transformation of the signal light such that a zero-order component of the signal light comes into focus at a point removed from the optical recording medium, forming a diffraction grating in the optical recording medium by interference between the zero-order component of the signal light and a high-order component thereof, and recording digital data represented by the signal light as a hologram.

Abstract: An optical recording method includes providing an optical recording medium capable of forming both a refractive index grating and an absorption grating by light irradiation; Fourier transforming with the same lens a signal beam that represents binary digital data with a brightness image and a reference beam such that they are focused at a point outside the optical recording medium; irradiating the Fourier transformed signal beam and reference beam simultaneously onto the optical recording medium and forming a diffraction grating at the optical recording medium according to an interference fringe between the signal beam and the reference beam, or according to an interference fringe within the signal beam itself; and recording the signal beam as a hologram.

Abstract: An image reading apparatus includes: a light source that irradiates light; a switching unit that switches a direction of the light irradiated by the light source to one of a plurality of predetermined directions; a light guiding unit that guides the light whose direction is switched by the switching unit and that travels in one of the plurality of directions to a position predetermined for each of the directions; and a light sensor that, in a case where an object is in the predetermined position, measures light reflect by the object out of the light guided to the position by the light guiding unit.

Abstract: A hologram recording apparatus includes a light source for irradiating coherent light, light separator for separating the coherent light into light for reference beam and light for signal beam, optical path changer for changing an optical path of each light separated by the light separator so that the reference beam and the signal beam may be irradiated simultaneously onto an optical recording medium, a spatial light modulator disposed in the optical path of the light for the signal beam for modulating the light for the signal beam in accordance with a supplied recording signal to create signal beam for recording a hologram, and diffused light irradiator for irradiating diffused light simultaneously with the reference beam at least onto an area of the optical recording medium where the reference beam is irradiated.

Abstract: The present invention provides an optical information reading device includes: a light source that irradiates, with reference beam, a hologram recorded in an optical recording medium; a reading unit that reads information from a holographic image reconstructed by the reference beam being diffracted by the hologram; a housing; a contact member of the housing contacting a paper; an open portion formed in the contact member, through which the optical recording medium is exposed and towards which the reference beam is emitted; an alignment mark formed at a periphery of the open portion, the reference beam irradiating the hologram satisfying a holographic image reconstruction condition by the alignment mark being aligned with an optical recording medium alignment mark recorded on the optical recording medium; and a viewing portion that is positioned in the housing and through which the alignment mark and the optical recording medium alignment mark are visible.

Abstract: There is provided an optical reproduction device that reproduces a hologram that is recorded on an optical recording medium by interference between a signal light and a reference light coaxial to the signal light. The device has: a coherent light source; a light distribution unit distributing light from the light source, to a signal light optical path and a reference light optical path; a spatial light modulator that includes a signal light region and a reference light region, a spatial light modulator, a first irradiation optical system spatially separating light distributed to the reference light optical path and light distributed to the signal light optical path, making optical axes of both lights coincide, and irradiating the both lights onto the spatial light modulator; and a second irradiation optical system irradiating reference light onto the optical recording medium as reading light, and reproducing the hologram.

Abstract: A hologram-recording material, including a photoresponsive molecule, a reactive molecule having an intrinsic birefringence, and a photopolymerization initiator that accelerates polymerization and/or crosslinking of the reactive molecule having an intrinsic birefringence, a content of the photopolymerization initiator being in a range of less than about 0.1 wt % relative to the hologram-recording material, and, a content of the reactive molecule having an intrinsic birefringence being in a range of about 30 to about 80 wt % relative to the hologram-recording material.

Abstract: An optical recording device includes a light source, a spatial light modulator, a correcting optical system and a light guiding section. The spatial light modulator includes plural pixels, a signal light region that displays a signal light pattern, and a reference light region that displays a reference light pattern. The spatial light modulator modulates and outputs incident light for each pixel in accordance with a display pattern. The correcting optical system includes a pair of axicon lenses that correct the emitted light from the light source so as to flatten the light intensity distribution thereof on an irradiated surface of the spatial light modulator. The light guiding section guides the corrected light to the spatial light modulator. The signal light and the reference light are irradiated onto an optical recording medium simultaneously and a hologram is recorded into the optical recording medium.

Abstract: A hologram recording method, which records signal light onto an optical recording medium as a hologram, includes: placing a signal light region, which generates signal light, and a reference light region, which generates reference light, symmetrically with respect to an optical axis of coherent light by displaying, on a spatial light modulator which spatially modulates the incident coherent light, a pattern which divides a modulating region into a plurality of regions; generating signal light and reference light by modulating the incident coherent light by the spatial light modulator; simultaneously and coaxially illuminating, onto a reflecting-type optical recording medium, the signal light and the reference light generated from the signal light region and the reference light region disposed symmetrically to one another; and recording the signal light on the optical recording medium as a hologram.

Abstract: An optical recording device includes a light source, a light-converging optical system, a moving unit, detection unit, and an acquisition unit. In the optical recording device, interference fringes from a recording light are shift multi-recorded as a plurality of pages of holograms within each of a plurality of planes corresponding to a plurality of convergence positions based on light exposure amount of each page, acquired by the acquisition unit, for each of the convergence positions.

Abstract: A hologram recording method includes eliminating a DC component from a Fourier transformation image of a signal light for expressing binary digital data as a brightness image, and irradiating an optical recording medium simultaneously with the signal light from which the DC component has been eliminated and a reference light to record an image edge portion of the signal light onto the optical recording medium as a hologram.

Abstract: A hologram recording method comprising recording information of signal light as a reflection-type hologram on an optical recording medium, by illuminating the signal light and reference light on a same axis and from different sides of the optical recording medium is provided. Further, a hologram recording device including: a signal light illuminating section illuminating signal light onto an optical recording medium; and a reference light illuminating section illuminating reference light of a same axis as the signal light, onto the optical recording medium from a different side than the signal light is provided.

Abstract: A hologram recording method for recording information of signal light as holograms in an optical recording medium, which includes illuminating signal light at the optical recording medium; illuminating reference light at the optical recording medium simultaneously with the signal light such that an interference pattern is formed by the signal light and the reference light intersecting in the optical recording medium; and shifting a region in the optical recording medium at which the signal light and the reference light intersect, by shifting an illumination position of the reference light along an optical axis of the signal light, thereby recording a plurality of holograms in the recording medium.

Abstract: A hologram reproduction method for reproducing a hologram from an optical recording medium in which the hologram is recorded by Fourier transforming a signal light, in which digital data is represented by an image of intensity distribution, and a reference light, and simultaneously irradiating the lights in a state in which a direct current component is removed from at least the Fourier transformed signal light onto the optical recording medium is provided. The method including: irradiating a read out reference light onto the optical recording medium, and generating a diffracted light from the recorded hologram; generating all or a part of a direct current component contained in a Fourier transformed image of the signal light; combining the diffracted light and the generated all or a part of the direct current component, and generating a combined beam; and reproducing the signal light by inverse-Fourier transforming the combined beam.

Abstract: A hologram reading apparatus includes: a unit holding a hologram recording medium in which data page is recorded by irradiating as a single beam both reference light and signal light modulated by a spatial light modulator including a first pixel area for modulating the reference light and a second pixel area for modulating the signal light, a pitch of pixels in the first pixel area being different from that in the second pixel area; a Fourier transform lens subjecting reproduction light to a Fourier transformation; a filter disposed on a Fourier transform plane of the reproduction light by the Fourier transform lens, the filter shielding the reference light at a first spatial frequency band and transmitting the signal light at a second spatial frequency band; and a reading unit receiving the reproduction light transmitted through the filter and reading the data page modulated to the signal light included in the reproduction light.

Abstract: An optical apparatus includes: a focusing lens that focuses light which is one of recording light being irradiated to an optical recording medium with reference light for recording a hologram and reference light being irradiated to an optical recording medium for reading out a hologram; and a focal position-shifting unit that refracts the light while moving in accordance with a moving speed of the optical recording medium, so as to shift a focal position of the light in the optical recording medium a distance in a thickness direction of the optical recording medium.

Abstract: A hologram reading apparatus includes: a unit for holding a hologram recording medium in which data page is recorded by irradiating as a single beam both reference light and signal light modulated by a spatial light modulator including a first pixel area for modulating the reference light and a second pixel area for modulating the signal light, a direction of an arrangement period of pixels in the first pixel area being different from that in the second pixel area; a Fourier transform lens subjecting reproduction light to a Fourier transformation; a filter disposed shielding the reference light at a first spatial frequency band and transmitting the signal light at a second spatial frequency band; and a unit for receiving the reproduction light and reading the data page modulated to the signal light included in the reproduction light.

Abstract: A hologram-recording method including recording a reflection-type volume hologram onto an optical recording medium by irradiating the optical recording medium with a modulated beam obtained by spatially modulating a laser beam and a diffused beam obtained by diffusing the modulated beam, coaxially but from different sides of the optical recording medium, respectively. The invention provides a hologram-recording method, an optical recording medium, and a hologram-recording device that enables on-demand recording of a reflection-type volume hologram which reliably prohibits forgery or alteration with a simple device configuration.