摘要:
Optical information is stored in an optical information recording medium having an information recording layer utilizing holography with an optical information recording apparatus which includes security features. An input device is used to input individual information which is unique to an individual. An information light carries information to be recorded on the optical information recording medium. A phase modulation pattern is generated based on the individual information. A recording reference light is generated including a phase modulator for spatially modulating a phase of the reference light, for generating reference light for recording having a phase spatially modulated based on the phase modulation pattern information. A recording optical system illuminates the information recording layer on the same side with both the information light and the reference light.
摘要:
A method for recording information on a recording medium utilizing an interference pattern by interference between an information light modulated spatially with digital pattern information displayed on a spatial light modulator having multiple pixels and a reference light for recording. In order to provide a novel recording method capable of enhancing the recording density and the transfer rate furthermore, digital information to be recorded is represented by match/mismatch of the attributes of adjacent pixels in the spatial light modulator to produce digital pattern information.
摘要:
It is an object of the invention to improve a recording capacity density by removing part of diffracted light and by making a recording region in relation to a recording medium in the efficient shape. An optical information recording apparatus in which holography is formed in an optical information recording medium by making information light reflected by a spatial modulator interfere with reference light, is provided with a diffracted light removal means which removes part of diffracted light of the reflected light, and whose aperture is in the shape of a square.
摘要:
An outgoing light beam from a laser light source 42 of a laser module 41 is radiated via a light polarizing hologram 51 on a two-segment optical rotation plate 52 of a movable unit. The two-segment optical rotation plate 52 is comprised of a right rotation plate 52R and a left rotation plate 52L divided along a line extending along the radius of an optical disc with the optical axis as the center, and rotates the outgoing light from the laser light source 42 by pre-set angles. The two-segment rotation plate 52 is arranged between the light polarizing hologram 51 and an objective lens 53. The outgoing light, rotated by the two-segment rotation plate 52, is radiated on the optical disc 33 via the objective lens 53. The reflected light from the light polarizing hologram 51 is passed via the objective lens 53 to the two-segment rotation plate 52 so as to be rotated further by pre-set angles by the right rotation plate 52R and the left rotation plate 52L. The light polarizing hologram 51 bends the light path of the outgoing light from the optical disc 33, rotated by the two-segment rotation plate 52, responsive to the direction of light polarization, and radiates the outgoing light. The focusing error signals (FE signals) or magneto-optical signals (MO signals) are derived on the basis of detection signals by photodetectors 44 to 48 receiving the reflected light from the optical disc 33 incident via the light polarizing hologram 51.
摘要:
A recording medium such as an optical or magneto-optical disk divided into servo areas and data areas, wherein at least one of pits in each servo area is formed with a phase deviation. There are also disclosed a method of recording pits on such a recording medium, and an apparatus for recording data on and/or reproducing the same from the recording medium. The apparatus comprises a light source for irradiating a light output to the recording medium; a photoelectric conversion means for receiving the light emitted from the light source and reflected from or transmitted through the recording medium, and converting the received light into an RF signal; a signal conversion means for converting the output RF signal of the photoelectric conversion means into a binary signal corresponding to the pit formed on the recording medium; and a detection means for detecting the servo area on the recording medium on the basis of the phase deviation of the binary signal outputted from the signal conversion means; wherein data is recorded or reproduced while a servo action is executed in accordance with the servo byte in the servo area detected by the detection means. The servo area is detectable with facility, and data of any pit pattern can be recorded and/or reproduced properly.
摘要:
In an optical pickup apparatus, including a laser source (11) arranged along an optical axis (0-0'), a polarization beam splitter (14) and an objective lens (13), wherein light emitted from the laser source (11) is emitted on a recording plane (1a) of an optical-magnetical recording media (1) as a converged beam, light beams reflected from the recording media (1a) of the optical-magnetical recording media (1) are separated by said polarization beam splitter (14) to obtain a predetermined polarized light component, a phase change means, which changes a phase of light passing through one side of said optical axis (0-0') and a phase of light passing through another side of said optical axis (0-0') by a predetermined angle, such as 1/2 wavelength plate (15), a phase retardation type prism (39) and a combination optical rotation plate (52), is provided between the polarization beam splitter (14) and the objective lens (13), and, an optical detection element, which detects the light polarized by the polarization beam splitter (14), is provided at a side intersecting the phase change means of the polarization beam splitter (14).
摘要:
The present invention relates to a laser reproducing apparatus which reproduces recorded data recorded on a recording medium such as an optical disc, a magneto-optical disc or the like by the irradiation of a laser beam, in which the current value of a driving signal which drives a laser diode (12) is set near a value at which there is the least interference with the laser beam is by reflected-back light from the recording medium, and the irradiation by the laser beam from the laser diode (12) at the thus set current value is intermittently carried out at predetermined intervals. Also, the duration of lock pulse of this laser beam is selected to be a duration in which writing on the recording medium (11) cannot be carried out by the thus set current value. Thus, the influence exerted on the laser beam by the reflected-back light from the recording medium (11) is small so that the data can be reproduced satisfactorily. Also, the arrangement of the drive circuit for driving the laser diode (12) can be simplified.
摘要:
A magnetooptical recording apparatus is disclosed which is capable of performing real-time overwrite operation. The apparatus comprises a laser beam and focusing parts thereof, and a pulse magnetic field generator device, procided on both sides of a magnetooptical recording medium, respectively. The laser beam and focusing parts thereof are formed of an objective lens connected to a moving coil which is provided with a magnet, thus the objective lens is movable relative to a magnetic layer of the magnetooptical recording medium by the interaction between the magnet and the moving coil. The magnet generates and applies a D.C. magnetic field of one polarity perpendicular to the magnetic thin film around a point where the laser beam is focused, while the pulse magnetic field generator device generates pulse magnetic field of the opposite polarity modulated by information signal around the point where the laser beam is focused. Thus one and opposite polarity magnetic field pulse row obtained by a sum of the D.C. magnetic field and the pulse magnetic field is applied to the magnetic thin film upon laser beam irradiation to perform the real-time overwrite operation.
摘要:
The present invention relates to a magneto-optical recording apparatus, for example, as shown in FIG. 3, which is capable of rewriting information written in a magneto-optical recording medium by overwriting, wherein the magneto-optical recording medium 1 is irradiated with a laser light LB corresponding to an information signal only when the magneto-optical recording medium 1 is applied with a magnetic field sufficient to invert the magnetizing direction of the magneto-optical recording medium 1, whereby a noise-up region is prevented from being formed and high density recording can be satisfactorily carried out.
摘要:
Provided is a three-dimensional image projector capable of displaying a highly reproducible three-dimensional image in response to changes in a viewer's position and easily accomplishing system downsizing. The three-dimensional image projector 1 includes: a projection image forming disc 4 in which hologram sheets 9a, 9b, 9c are laminated along inner surfaces 10a, 10b of glass substrates 8a, 8b, and which projects image light by causing the image light having directivity to fall incident on the hologram sheets 9a, 9b, 9c; and a rotational drive unit 3 for rotationally driving the projection image forming disc 4 along a surface of the glass substrates 8a, 8b, with a center point C1 serving as the rotation center, wherein the hologram sheets 9a, 9b, 9c are preliminarily recorded with holograms 11a, 11b, 11c of a mode that are formed by causing reference light and object light as two laser beams L3, L2 to simultaneously fall incident on a position corresponding to the center point C1 while maintaining the incidence angle θ1 to the hologram sheets 9a, 9b, 9c to be substantially the same.