Hitachi Consumer Electronics Co., Ltd.

Hitachi, Ltd.

Hitachi High-Tech Corporation

Hitachi-Lg Data Storage, Inc.

Hitachi Media Electronics Co., Ltd.

Makoto Hosaka

Toshiki Ishii

Kenichi Shimada

Kenichiro Yamada

Yusuke Nakamura

Kazuyoshi Yamazaki

Taku Hoshizawa

Shinji Fujita

Shinsuke Onoe

Mayumi Nagayoshi

A surface shape detection device using differential interference optics achieves restoration error reduction of a surface shape while maintaining resolution. The surface shape detection device includes: a light spot scanning unit such as a wafer rotation direction drive unit that scans a wafer surface with a light spot; an interference light detection mechanism such as a differential interference optical system that detects interference light of light obtained by scanning a surface of an inspection target with a plurality of the light spots separated by a predetermined design distance; and a surface shape restoration processing unit such as a wafer surface shape restoration unit that samples, at a predetermined quantization time interval, and calculates information of the interference light, and performs restoration processing on a surface shape of the wafer, in which the predetermined design distance is larger than a quantization distance interval corresponding to the predetermined quantization time interval.

Surface shape detection device and detection method

The optical information recording device includes a light source configured to emit a laser beam, an optical element configured to divide the laser beam into the reference beam and the signal beam, an angle control unit configured to control an angle of incidence of the reference beam on the optical information recording medium, and a phase control unit configured to control a phase of at least one of the signal beam and the reference beam in a recording period, wherein the angle control unit controls an angle interval so that a position of a 1st null of an adjacent page of the signal beam is fixed, and wherein the phase control unit controls the phase of the signal beam or the reference beam so that a phase difference between the adjacent pages is a predetermined value.

Optical information recording device and optical information recording method

Provided are an optical information reproduction device and a method therefor with which the influence of reference light reflected from the surface of a disk can be reduced, thereby enabling data to be reproduced in a stable manner in an optical information reproduction device that uses holography. The information reproduction device, which reproduces from a recording medium information that has been recorded on the recording medium by the formation of a hologram, is equipped with: a light output unit that emits laser light; an optical system that generates reference light from the laser light emitted from the light output unit; an objective lens that reproduction signal light reproduced by the reference light with which the recording medium has been irradiated enters; a light detector that receives the reproduction signal light propagated by the objective lens; a medium-reflected light reduction unit that reduces the amount of medium-reflected light (generated when the recording medium reflects the reference light) with which the light detector is irradiated; and a control unit that controls the operation of the information reproduction device.

Optical information reproduction device and optical information reproduction method

An optical information recording/reproduction device is capable of appropriately correcting the angle of a reference beam during data reproduction even when a wavelength deviation or an angle deviation in multiplexing and vertical directions of the reference beam occurs in a holographic memory recording medium. The optical information reproduction device has a laser light source that generates a reference beam; an image-capturing unit that detects a diffraction ray to be reproduced from the optical information recoding medium; and an optical detection unit that has at least two light-receiving surfaces and is used for detecting a diffraction ray reproduced by irradiating the reference beam on the optical information recording medium. The device also has a light-shielding unit that shields part of the diffraction ray detected by the optical detection unit; and an error signal calculation unit that generates an error signal from a detection signal outputted by the optical detection unit.

An optical information reproduction apparatus using holography can appropriately correct an angle and a wavelength of a reference beam in a direction perpendicular to multiplexing while data is reproduced. In the optical information reproduction apparatus which reproduces information from an optical information recording medium by using holography, an angular error signal in the direction perpendicular to multiplexing of the reference beam is generated by using a signal detected by a light detecting unit. A perpendicular angle adjustment element adjusts an angle of the reference beam in the direction perpendicular to multiplexing, based on the angular error signal. A wavelength error signal is generated from a signal detected by the light detecting unit, and a wavelength is adjusted based on the wavelength error signal.

Optical information reproduction apparatus and optical information reproduction method

An optical information reproducing device, takes advantage of holography and can precisely detect a well-known pattern disposed at a prescribed location within a page and is used for correcting position deviation, rotation deviation, and magnification deviation. The optical fiber reproducing device includes a detection unit that detects the position information of a marker as a well-known pattern from a page as a 2-dimensional reproduction signal from a hologram, a detection error position estimating unit that estimates presence/absence of detection error in the position information of the marker and estimates the position where the detection error occurs if there is detection error, a position correcting unit that corrects the marker position information of the detection error position specified by the detection error position estimating unit, and a signal detection unit that detects each signal from within the page based on the corrected marker position information.

Optical information reproducing device

In an optical information recording/reproducing apparatus using holography, there are provided the optical information recording/reproducing apparatus, method thereof, and optical information recording medium which correct a zero point and variation of unit quantity of a reference beam angle between apparatus and perform recording or reproducing operation with high compatibility between apparatus. The optical information recording/reproducing apparatus detects a reference beam angle suitable to reproduce angle correction data recorded on the optical information recording medium and corrects a zero point and unit quantity of the reference beam angle at the time of recording or reproducing operation based on the detection angle information.

Optical information recording/reproducing apparatus, optical information recording/reproducing method, and optical information recording medium

The present invention provides a technology which estimates the most suitable cure time which changes with the environment when recording a hologram and adjusts the cure time in real time, thereby enabling a suitable pre-cure or post-cure. When irradiating an optical information recording medium with cure light, the light transmitted from the optical information recording medium is detected by a detector and the irradiation time is adjusted by continuing irradiation until the intensity of the transmitted light detected exceeds a prescribed reference value.

Optical information recording and reproduction device, optical information recording device, method for recording and reproducing optical information and optical information recording medium

In reproduction of a two-dimensional page data from an optical information recording medium utilizing holography, a reproduced two-dimensional page data is divided into a plurality of areas each of which has a predetermined size, the divided two-dimensional areas are individually subjected to adaptive equalizing, and then are coupled to restore the condition of the original two-dimensional page data.

Optical information reproducing apparatus and optical information reproducing method

An optical information recording/reproducing apparatus, to apply holograms of an angle multiplex recording method therein includes: a light source to emit a light beam; a divider unit to divide the light beam into a signal beam and a reference light; an angle variable unit to change an angle of the reference light incident upon an optical information recording medium; a spatial light modulator unit to add information to the signal beam; an objective lens to irradiate the signal beam on the medium; an image pickup unit to detect a diffracted light generating from a recording region, when the reference light is irradiated on the medium; and an optical element to shape a form of light flux of the reference light, so that a light flux diameter of the reference light in a multiplex direction becomes larger than the light flux diameter of the reference light in a pitch direction.

Optical information recording/reproducing apparatus

In an optical information reproduction method for reproducing information using holography from a medium which records an interference pattern generated when overlapping a signal beam and a reference beam, the reference beam is radiated to the medium at a reference beam angle with a predetermined range for reproducing the information, a reproduction beam is generated by diffracting the reference beam with the interference pattern, the reproduction beam is detected by a photodetector; and the information is reproduced by processing a signal detected by the photodetector.

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Tokyo, Japan

Makoto Hosaka