Abstract: A hologram recorder is provided, in which coherent light from a light source is split into a signal beam and a reference beam, and the signal beam is modulated by a spatial light modulator to be directed to a hologram recording medium, while the reference beam is directed to the hologram recording medium to overlap with the signal beam for recording a hologram on the hologram recording medium. The hologram recorder includes a beam phase modulator provided with a plurality of optical devices (20p, 20p?) each configured to assume one of two modes such as ON mode and OFF mode, the ON mode for causing the reference beam to be passed or reflected in a predetermined direction toward the hologram recording medium, the OFF mode for causing the reference beam to be blocked or directed in another direction other than the predetermined direction. Each optical device (20p, 20p?) provides a phase difference 0 or ?.

Abstract: A holographic recorder can vary the optical distance between an object lens and a relay lens near the object lens. This arrangement allows defocus-multiplexing utilizing state variations in the laser beam when the beam reaches a storage medium.

Abstract: A hologram recorder (A) which records holograms by causing a recording beam (P) and a reference beam (S) to interfere with each other in a hologram recording media (B), includes an incident-side and an emitting-side lenses (3a, 3b) provided as a compound lens disposed in a laser beam path between a light source (1) and a beam separator (7); and an aperture stop (5) provided to limit a light flux diameter between the incident-side and emitting-side lenses (3a, 3b). The aperture stop (5) is disposed at a position biased toward the incident-side lens (3a) as viewed from an incident-side focal position of the emitting-side lens (3b).

Abstract: A hologram recorder records a hologram in a hologram recording medium by interference of a recording beam irradiated at a predetermined incident angle to the medium via a spatial light modulator incliningly in a predetermined direction with a reference beam irradiated incliningly in an opposite direction to the recording beam so that the beams crosses at a predetermined crossing angle. The recorder includes a beam modulator for converting a Gaussian-beam having a Gaussian-distribution of intensity into a parallel beam having an intensity distribution tending to be uniform and allowing the parallel beam to travel to the spatial modulator as the recording beam. The Gaussian-beam has a center axis decentered from an optical axis of the beam modulator in a decentering direction including a directional component of the predetermined direction in which the recording beam is inclined or an opposite directional component thereto.

Abstract: The hologram recording/reproducing apparatus is for recording a hologram by emitting a recording beam (S) modulated by a spatial light modulator and a reference beam (R) having a same wavelength as the recording beam onto a hologram recording medium (B) so that the beams overlap each other with polarization direction (p) of the beams being matched to interfere with each other, and for reproducing the hologram by exposing the hologram recording medium storing the hologram to the reference beam to generate diffracted light and receiving the diffracted light by an imaging device. The spatial light modulator is controlled so as to form a data area (H0) corresponding to information to be recorded and a plurality of mark areas (H1) for detecting a position of the data area in the hologram recording medium (B) in recording of the hologram.

Abstract: A hologram recorder applies a recording beam (S) and a reference beam (R) to the illumination site (p) of a hologram recording medium (B). The interference between the recording beam (S) and the reference beam (R) produces multiple hologram recording at the illumination site (p). The recorder includes a recording-purpose reference beam reflector (10) for reflecting the reference beam (R) to the illumination site (p), and a pivot mechanism for pivoting the reflector (10) about an axis (x) to vary the incident angle (?r) of the reflected reference beam (R) to the recording medium (B). The reflector (10) is disposed to cross a predetermined optical path. The axis (x) of the pivot mechanism is so arranged that the reflected reference beam (R) is directed to the illumination site (p) even when the incident angle (?r) of the beam (R) changes due to the pivoting of the reflector (10).

Abstract: A hologram recording device (A1) includes a laser (1), a beam splitter (3) splitting the laser beam from the laser (1) into recording and reference beams (S), (R), a spatial light modulator (5) modulating the recording beam (S) by record information, a recording opto-system directing the modulated beam (S) to a target site of a hologram recording medium (B), and a reference opto-system directing the reference beam (R) to the target site of the recording medium (B) for interference with the recording beam (S) through difference incident angles. The beam (S)-beam (R) interference enables multiplex hologram recording at the target site. The device (A1) further includes a light amount adjustor (8) that adjusts the amount of the reference beam (R) from the splitter (3) based on the incident angle to the recording medium (B) for keeping the illuminance of the reference beam (R) at the target site at a predetermined level.

Abstract: A hologram recording device illuminates with a recording beam (S) a hologram recording medium (B), and illuminates with a reference beam (R) a region illuminated with the recording beam (p) while variably controlling the incident angle regarding the hologram recording medium (B) whereby holograms are recorded on the illuminated region (p) in multiple by interference of the recording beam (S) and the reference beam (R). The device includes an incident angle variable controller for variably controlling the incident angle of the reference beam (R) in a predetermined range. The hologram recording medium (B) has such characteristics that its recording sensitivity degrades as the incoming light amount increases. The incident angle variable controller changes the incident angle of the reference beam (R) from a larger angle to a smaller angle.

Abstract: A hologram recorder (A) records a hologram in a hologram recording medium (B) by interference of a recording beam (S) irradiated at a predetermined incident angle to the medium (B) via a spatial light modulator (2) incliningly in a predetermined direction with a reference beam (R) irradiated incliningly in an opposite direction to the recording beam (S) so that the beams (S,R) crosses at a predetermined crossing angle. The recorder includes a beam modulator (1) for converting a Gaussian-beam having a Gaussian-distribution of intensity into a parallel beam having an intensity distribution tending to be uniform and allowing the parallel beam to travel to the spatial modulator (2) as the recording beam (S). The Gaussian-beam has a center axis (Gs) decentered from an optical axis (1A) of the beam modulator (1) in a decentering direction including a directional component of the predetermined direction in which the recording beam (S) is inclined or an opposite directional component thereto.

Abstract: A hologram recording device for irradiating a recording beam (S) to a hologram recording medium (B) at a fixed incident angle (?s) and irradiating a reference beam (R) to an illuminated region (p) of the recording beam (S) by variably controlling an incident angle (?r) of the reference beam (R) on the hologram recording medium (B), whereby a hologram is recorded on the illuminated region (p) in multiple, includes at least a variable reflector (10) directing the reference beam (R) to the illuminated region by reflection and being swung around a predetermined axis (x) for changing the incident angle (?r) of the reference beam (R); and a light shield (11) being swung integrally with the variable reflector (10) for partially shielding the reference beam (R) so that a luminous flux diameter thereof becomes narrower as the incident angle (?r) becomes larger.

Abstract: A holographic recorder (A1) can vary the optical distance between an object lens (8) and a relay lens (7b) near the object lens (8). This arrangement allows defocus-multiplexing utilizing state variations in the laser beam when the beam reaches a storage medium (B1).

Abstract: A hologram recorder (A) records holograms in a selected unit recording area (B1) of a hologram recording medium (B) by interference between a recording beam (Lr) which is applied vertically to the unit recording area (B1) and a reference beam (Lr) which is applied obliquely to the unit recording area (B1). The hologram recorder (A) includes a reference beam oblique applier (23A, 23B) for application of the reference beam (Lr) obliquely to the unit recording area (B1) by reflection, and a reference beam swing mechanism (30) for supporting the reference beam oblique applier (23A, 23B) and for swinging the reference beam oblique applier (23A, 23B) about a predetermined rotation axis which is perpendicular to an entering direction of the recording beam (Lw) that makes an entry into the unit recording area.

Abstract: A hologram recorder is provided, in which coherent light from a light source is split into a signal beam and a reference beam, and the signal beam is modulated by a spatial light modulator to be directed to a hologram recording medium, while the reference beam is directed to the hologram recording medium to overlap with the signal beam for recording a hologram on the hologram recording medium. The hologram recorder includes a beam phase modulator provided with a plurality of optical devices (20p, 20p?) each configured to assume one of two modes such as ON mode and OFF mode, the ON mode for causing the reference beam to be passed or reflected in a predetermined direction toward the hologram recording medium, the OFF mode for causing the reference beam to be blocked or directed in another direction other than the predetermined direction. Each optical device (20p, 20p?) provides a phase difference 0 or ?.

Abstract: A hologram recorder includes a light source for emitting a laser beam, a polarizing beam splitter for splitting the laser beam into a recording beam and a reference beam in accordance with a state of polarization, and a rotary polarizer located between the light source and the polarizing beam splitter. The rotary polarizer has the function of optical rotation, whereby a polarization component to be the recording beam is increased from the central portion toward the peripheral portion of the laser beam, and a polarization component to be the reference beam is decreased from the central portion toward the peripheral portion of the laser beam.

Abstract: A hologram recorder (A2) includes: a light source (10) for emitting a coherent beam; a spatial light modulator (20) provided with unit areas having a plurality of beam reflection elements (21) to reflect the beam from the light source (10) in a main direction as a signal beam or a cut-off direction; and a signal beam optical system (30, 31) for directing the signal beam to the hologram recording medium B. The recorder (A2) further includes: a wavefront reshaper (40, 41, 42) for condensing the beams thinned out in the cut-off direction by the beam reflection element (21) of the modulator (20), and reshaping the wavefront of the condensed beams; and a reference beam optical system (50, 51) for directing the beam from the reshaper (40, 41, 42) to the recording medium (B) as a reference beam to be shone in an overlapping manner with the signal beam.

Abstract: A magneto-optical recording medium (X1) comprises a substrate (S1) and a material film structure. The substrate (S1) includes a pre-groove surface (11a) with a pre-groove (11b) formed therein, and at least the pre-groove surface (11a) is made of a soft magnetic material. The material film structure comprises a recording magnetic section (21) for executing a recording function and a reproduction function and is provided on a pre-groove surface (11a) of the substrate (S1).

Abstract: A disc cleaner includes a disc rotation mechanism that rotates a disc (A), a cleaning member (14) for cleaning a reading surface during the rotation of the disc (A) and a press member that brings the cleaning member (14) into contact with a press member (16). The disc cleaner is provided with a movement mechanism that moves the press member (16) along the radical direction of the disc (A) during cleaning when the disc (A) rotates, and that allows the press member (16) to reach the outside of the recording region of the disc (A) when cleaning is completed.

Abstract: An optical disk cartridge includes a cartridge body formed with an opening at an edge thereof such that an optical disk can be taken out and returned from and to the optical disk cartridge. The opening is closed by a cover lid that is formed as an integral body of the cartridge body.