Abstract: A two-dimensional digital data acquisition element includes: a pixel area having a plurality of pixels arranged in a matrix form, each of the pixels having a photoelectric conversion element to convert the reproduced light from the optical information recording medium to an electric signal; selection circuits which select the pixel; a readout circuit which reads out an electric signal of a pixel selected by the selection circuits; and a 1-bit AD converter which converts an output of the readout circuit to 1-bit digital data. A pitch ratio N between a pitch P1 of the unit data areas in the two-dimensional digital image information and a pitch P2 of the pixels in the pixel area defined as N=P1/P2 satisfies a relation A·n2/(An+1)<N<A·n2/(An?1) where A is the number of digital data in one-dimensional direction of one byte of the two-dimensional digital data and n is a natural number of at least 2.

Abstract: An optical recording medium includes a first substrate having a groove on the side of an outer peripheral portion thereof; a second substrate in contact with the first substrate in the outer peripheral portion; and a recording layer being disposed in a gap between the first substrate and the second substrate and forming a void in cooperation with the first substrate at the portion of the groove.

Abstract: An optical-information recording medium includes a substrate that includes a servo surface having a servo pattern thereon; an information recording layer laminated on the servo surface of the substrate capable of recording information as a hologram produced by interference between an information beam containing the information and a reference beam; an address servo area that is formed as a part of the servo pattern, and that records therein address information and clock information for aligning a beam, emitted from an optical-information recording apparatus for recording information in the information recording layer, to a target position in the information recording layer; and a following up servo area that is formed as a part of the servo pattern, and that is to be irradiated by the beam to make the beam follow a rotation of the optical-information recording medium.

Abstract: A method of holographic recording and reproduction includes recording to the holographic recording medium a wavelength variation reference pattern which is recorded as a hologram at a wavelength of the recording beam, recording to the holographic recording medium a page data pattern as a hologram at the wavelength of the recording beam, detecting the wavelength variation between the recording beam and the reproducing beam based on the size of an image for wavelength variation reference obtained by reproducing the wavelength variation reference pattern at a wavelength of the reproducing beam, and reproducing the page data pattern using the reproducing beam with a wavelength controlled based on the detected wavelength variation.

Abstract: The optical information recording medium according to the present invention includes a transparent substrate having a first surface and a second surface, a recording layer that is arranged on the first surface of the transparent substrate, and a reflection layer arranged on the second surface of the transparent substrate. A hologram is recorded in the recording layer when a signal light and a reference light are incident from an incident side opposite to the transparent substrate. An optical density of the recording layer corresponding to the signal light decreases from the incident side toward the transparent substrate.

Abstract: A holographic recording medium has a recording layer including a radical-polymerizable compound, a first photo-radical polymerization initiator (A) containing a titanocene compound, and a second photo-radical polymerization initiator (B) containing at least one compound selected from the group consisting of an amino acetophenone derivative, an acylphosphine oxide derivative, a benzyl derivative, and a thioxanthone derivative.

Abstract: A hologram recording/reproducing apparatus includes a recording/reproducing optical system that guides at least one of an information beam and a reference beam to an optical recording medium; a spatial light modulator that is arranged in an optical path of the recording/reproducing optical system, and spatially modulates a beam guided via the recording/reproducing optical system to generate the information beam; a first misalignment detecting unit that detects a first misalignment between the recording/reproducing optical system and the spatial light modulator using a beam for detecting the first misalignment; and a first misalignment correcting unit that corrects the first misalignment based on the first misalignment detected by the first misalignment detecting unit.

Abstract: A holographic recording medium is provided, which includes a recording layer including a radically polymerizable monomer having an ethylenically unsaturated bond, a photo-acid generator, a photo-radical polymerization initiator, and a polymeric matrix. The polymeric matrix includes a repeating unit expressed by any one of the following chemical formulae.

Abstract: An optical-information recording medium includes a substrate that includes a servo surface; an information recording layer laminated on the servo surface of the substrate capable of recording information as a hologram produced by interference between an information beam containing the information and a reference beam; a tracking servo area that is formed in a track direction on the servo surface, and that records therein tracking information for tracking servo control; and a following up servo area that is formed in the track direction on the servo surface, and that is to be irradiated by a beam emitted from an optical-information recording apparatus for recording the information in the information recording layer so as to make the beam follow a rotation of the optical-information recording medium.

Abstract: The present invention relates to a method for optical recording in which information is recorded on an optical recording media utilizing holography and to a method for optical reproducing in which information recorded on an optical recording media utilizing holography is reconstructed. The methods includes preparing an optical recording media having wavelength reference marks with a periodic structure which are associated with a recording base wavelength, irradiating the wavelength reference marks with a beam from a light source on recording information or on reproducing information to detect a wavelength shift of the light source with respect to the base wavelength based on a diffraction beam from the wavelength reference marks, and performing recording or reproducing while controlling the wavelength of the light source so as to reduce the wavelength shift.

Abstract: An optical recording/reproducing apparatus includes an optical recording medium in which a holograms are recorded depending on an incident angle of a reference beam. The reference beam is irradiated to holograms while changing the incident angle to generate a reproduction light beam, and an image patterns are detected by an image pattern detector. The continuously output reproduction image patterns are temporarily stored in an image recorder, and the maximum value of reproduction light intensity is detected to generate a trigger signal. Depending on the trigger signal, an optimal image pattern is extracted from continuous reproduction image patterns, and thus, two-dimensional data is decoded.

Abstract: Disclosed is a holographic recording medium and methods of manufacturing the holographic recording medium. The example of the medium has a recording layer containing a three dimensionally cross-linked polymer matrix including an epoxy resin, a radically polymerizable monomer, and a photo radical polymerization initiator. The radically polymerizable monomer comprises both N-vinylcarbazole (VC) and N-vinylpyrrolidone (VP) or N-vinylcarbazole alone. The weight ratio of N-vinylcarbazole (VC) to the sum of N-vinylcarbazole (VC) and N-vinylpyrrolidone (VP), i.e., (VC/(VC+VP)), is not smaller than 0.75 and not larger than 1.0.

Abstract: A holographic recording medium is provided, which includes a recording layer. The recording layer comprises a radical polymeric monomer having an aromatic ring-containing group and a polymeric group, a polymer matrix having the aromatic ring-containing group, and a photo-radical polymerization initiator.

Abstract: Disclosed is a holographic optical recording medium, comprising a recording layer containing a three dimensionally cross-linked polymer matrix, a radically polymerizable compound, and a photo radical polymerization initiator, the three dimensionally cross-linked polymer matrix comprising a cured material of a reaction product between a diglycidyl ether and an amine, the diglycidyl ether being selected from the group consisting of 1,6-hexanediol diglycidyl ether and diethylene glycol diglycidyl ether.

Abstract: A two-dimensional digital data acquisition element includes: a pixel area having a plurality of pixels arranged in a matrix form, each of the pixels having a photoelectric conversion element to convert the reproduced light from the optical information recording medium to an electric signal; selection circuits which select the pixel; a readout circuit which reads out an electric signal of a pixel selected by the selection circuits; and a 1-bit AD converter which converts an output of the readout circuit to 1-bit digital data. A pitch ratio N between a pitch P1 of the unit data areas in the two-dimensional digital image information and a pitch P2 of the pixels in the pixel area defined as N=P1/P2 satisfies a relation A·n2/(An+1)<N<A·n2/(An?1) where A is the number of digital data in one-dimensional direction of one byte of the two-dimensional digital data and n is a natural number of at least 2.

Abstract: An optical recording medium includes a first substrate having a groove on the side of an outer peripheral portion thereof; a second substrate in contact with the first substrate in the outer peripheral portion; and a recording layer being disposed in a gap between the first substrate and the second substrate and forming a void in cooperation with the first substrate at the portion of the groove.

Abstract: According to an aspect of the present invention, there is provided an optical recording medium including a first substrate, a first adjusting layer, an organic recording layer, a second adjusting layer and a second substrate, sequentially stacked in the mentioned order. The first and second substrates have a refractive index of n1. The organic recording layer has a refractive index of n2. The first and second adjusting layers have a thickness of k and a refractive index distribution in a range of ns from a minimum value on sides contacting with the organic recording layer to a maximum value on sides contacting respectively with the first and second substrates. ns satisfies n2?ns?n1, and k satisfies 5?k?200 nm.

Abstract: A holographic recording medium is provided, which includes a recording layer comprising a three-dimensional cross-linking polymer matrix, a radical polymeric compound, and a photo-radical polymerization initiator. The three-dimensional cross-linking polymer matrix is represented by the following general formula (1): where m is an integer ranging from 3 to 16.

Abstract: Disclosed is a holographic optical recording medium comprising a recording layer having a skeleton structure represented by following general formula (A): where R1 denotes an atomic group selected from the group consisting of a linear or branched alkylene group having 1 to 10 carbon atoms and an arylene group having 1 to 10 carbon atoms, it being possible for a halogen atom or an alkoxy group to be substituted in R1, and each of p and q is 0 or 1.

Abstract: Provided is a holographic recording medium including a recording layer in which information is to be holographically recorded, and a light-shielding layer which faces a main surface of the recording layer. The transmittance of the light-shielding layer for a recording light is increased on increasing intensity of the recording light. Alternatively, the light-shielding layer selectively transmits the recording light.