Patent application number | Description | Published |
20080232203 | Optical Pickup - An optical pickup projects laser beams having the first to the third wavelengths, in response to the type of a recording medium which is an object to which recording or reproduction is to be performed, and reflecting light from the recording medium is received by a light-detecting element. In order to reduce the sizes of the optical pickup, light of the second and the third wavelengths is generated by a single dual-wavelength light source, and reflecting light of all the wavelengths is to be received by the single light-detecting element. A hologram element giving different optical effects to light of each wavelength is arranged between the light irradiating means and the light-detecting element. Thus, appropriate information recording and reproduction can be performed by using light of each wavelength. | 09-25-2008 |
20080239419 | Hologram Reproduction Apparatus and Hologram Reproduction Method - A hologram reproducing apparatus is provided that can be reduced in size. A hologram reproducing apparatus of the invention reproduces signal information from a recorded media having a domain of diffraction grating that is irradiated with a record light beam containing a coherent reference light component and a signal light component spatially modulated according to the signal information substantially on the same optical axis and is recorded an interference of the reference light component and the signal light component. The hologram reproducing apparatus comprises a light source for emitting a coherent light beam, a light-beam irradiator for irradiating the light beam to the domain of diffraction grating of the recording medium, a light collector for collecting a reproduced light beam reproduced by irradiating the light beam to the domain of diffraction grating toward a convergent position, an incident-light processing unit provided at the convergent position and for separating a Fourier 0-order component of the reproduced light beam and a diffraction light component of the reproduced light beam, and a detecting section for detecting the signal information from the diffraction component. | 10-02-2008 |
20080247010 | Hologram Recording and Reproducing Apparatus and Hologram Recording Method - There is provided a hologram recording and reproducing apparatus for a hologram recording medium that stores optical interference fringes therein as a diffraction grating generated by coherent reference light and signal light. The hologram recording and reproducing apparatus includes a control circuit that is connected to a spatial light modulator and controls each pixel in such a way that the reference light is modulated according to information data to produce the signal light. The control circuit spatially classifies a plurality of pixels in the spatial light modulator into a central modulation area disposed on the optical axis and at least one annular modulation area sequentially disposed around the central modulation area in a concentric manner, and controls the pixels in the central modulation area and the pixels in the annular modulation area using respective different recording modulation methods to deliver the signal light through the central modulation area and the annular modulation area. | 10-09-2008 |
20080279061 | Method for Recording and Reproducing a Hologram and Apparatus Therefor - A hologram recording method is a method of recording a hologram, on a hologram recording apparatus that records information by forming a diffraction grating through oppositely irradiating the signal beam and the reference beam to the hologram record carrier. The hologram recording method includes a step of focusing the reference beam at a first numerical aperture from a first effective diameter by means of the reference-beam objective lens, a step of separating the reference beam in a part on the optical axis and a neighborhood thereof to thereby produce from the reference beam a recording reference beam to passes through the hologram record carrier at a second numerical aperture smaller than the first numerical aperture from a second effective diameter smaller than the first effective diameter by means of the reference-beam objective lens of the reference-beam optical system, and allowing the recording reference beam to exit coaxially to the reference beam, and a step of not allowing only the recording reference beam to exit toward the hologram record carrier by means of the signal-beam optical system. | 11-13-2008 |
20080291807 | Hologram Record Carrier and Record Reproducing Method and System - A hologram recording carrier is provided with a hologram recording layer that stores inside an optical interference pattern made by components of irradiated coherent reference light and signal light, as a diffraction grating; and a polarization selective reflection film that is arranged on an opposite side to a light irradiation plane of the hologram recording layer and reflects a second linear polarization component rotated from a first linear polarization component, without reflecting the first linear polarization component of incident light. | 11-27-2008 |
20090129235 | OPTICAL PICKUP DEVICE - The present invention provides an optical pickup device requiring no position adjustment of a diffraction grating at the time of assembling the optical pickup device, and capable of suppressing fluctuations in a differential push-pull signal amplitude and cancelling a push-pull offset. | 05-21-2009 |
20090141325 | Hologram Device and Recording Method - A hologram apparatus capable of recording and reproduction of a recording medium with stability. The hologram apparatus includes: a suspension unit for holding a recording medium in a freely mountable fashion, the recording medium storing an optical interference pattern inside as a diffraction grating; a reference light optical system for emitting reference light toward the recording medium; and a signal light optical system for emitting signal light toward the recording medium, being arranged on a side opposite from the reference light optical system coaxially across the recording medium, the diffraction grating being formed by opposite irradiation of the recording medium with the signal light and the reference light. The hologram apparatus has: an objective lens for condensing the reference light with a first numerical aperture; and a spatial light modulation device for generating the signal light from the reference light past the recording medium and making it pass through the recording medium with a second numerical aperture different from the first numerical aperture, the signal light being modulated according to recorded information. | 06-04-2009 |
20090201787 | PICKUP DEVICE - A pickup device includes an irradiation optical system including an object lens for focusing light flux on a track of a recording surface of an optical recording media having a plurality of recording layers stacked while a spacer layer is interposed between the recording layers to form a spot and a detection optical system including an photo detector having a plurality of light receiving parts for receiving returning light reflected from the spot through the object lens to perform photoelectric conversion. The pickup device controls a position of the object leans according to an electrical signal calculated from outputs of the light receiving parts. The pickup device further includes an astigmatic device for providing astigmatism to the returning light directed to the light receiving parts and a division device, having divisional regions divided by a division line extending in an astigmatic direction about an optical axis of the returning light, for dividing the returning light having the astigmatism into a plurality of partial light fluxes divided for the respective divisional regions along the optical axis of returning light. The neighboring divisional regions provide the partial light fluxes with an optical action so that interference between the corresponding partial light fluxes does not occur on the light receiving parts. | 08-13-2009 |
20090245069 | RECORDING MEDIUM AND RECORDING SYSTEM - Disclosed herein is a recording medium on or from which the recording or reproduction of data is stably performed. On the recording medium, data are recorded three-dimensionally by the irradiation of a recording laser beam. The recording medium includes a reflection control layer including a plurality of reflection layers stacked in a film thickness direction, each reflection layer having a connection terminal, each reflection layer exhibiting reflectivity and transmissivity changeable in response to an electrical signal supplied to the connection terminal and a recording layer disposed at a beam incidence side of the reflection control layer. | 10-01-2009 |
20090262408 | OPTICAL PICKUP APPARATUS AND HOLOGRAM RECORDING AND REPRODUCING SYSTEM - An optical pickup apparatus includes a light source for generating a coherent beam, a spatial light modulator having a central region arranged on an optical axis of the coherent beam and an annular region arranged in a manner surrounding the central region, to spatially separate a transmission component of the coherent beam through the central region and a transmission component through the annular region thereby producing a reference beam and a signal beam and propagating those coaxially in a same direction, an objective lens optical system arranged on the optical axis and for illuminating the signal beam and the reference beam coaxially toward the hologram record layer and causing the reference beam and the signal beam to focus on focal points different from each other, image detecting means arranged on the optical axis and for receiving a beam returning from the hologram record layer through the objective lens optical system when the reference beam is illuminated to the hologram record layer; and a polarization-plane rotating device having a central polarizing region arranged on the optical axis and an annular polarizing region arranged in a manner surrounding the central polarizing region and for making transmission components through the central and annular polarizing regions different in rotation angle on the polarization plane from each other. | 10-22-2009 |
20090278029 | PICKUP DEVICE - A pickup device includes an irradiation optical system containing an objective lens for forming a spot by converging a light beam onto a track of a recording surface of an optical recording medium having a plurality of laminated recording layers; and a detection optical system containing a photodetector for receiving, through the objective lens, return light which was reflected and returned from the spot to perform a photoelectric conversion, in which a position of the objective lens is controlled in response to an electric signal arithmetically operated from an output of the photodetector. The photodetector includes a plurality of photosensing element groups which are arranged away from each other on a plane to which an optical axis of the return light penetrates perpendicularly and each of the groups is composed of a plurality of photosensing elements. The pickup device further comprises a dividing element disposed on another plane to which the optical axis of the return light penetrates perpendicularly. The dividing element has: at least two division regions which are formed so as to be line-symmetrical with respect to a track directional line which intersects with the optical axis of the return light and extends in parallel with the track; at least two division regions which are formed so as to be line-symmetrical with respect to a track vertical line which intersects with the optical axis of the return light and extends in the direction perpendicular to the track; and a center division region which includes the optical axis of the return light and is formed so as to be point-symmetrical with respect to the optical axis of the return light. The dividing element divides the return light into a plurality of partial light beams at respective division regions to deflecting the partial light beams from the division regions other than the center division region to the photosensing element groups. | 11-12-2009 |
20090310469 | OPTICAL PICKUP APPARATUS - An optical pickup apparatus reads an information signal recorded on a recording surface of an optical disk along a track by projecting a light beam. Said optical pickup apparatus has: an objective lens for converging said light beam onto said recording surface; an objective lens moving device for moving said objective lens in a radial direction of said optical disk; and a divisional photosensing device for receiving return light reflected by said optical disk, in a plurality of divided regions. Said divisional photosensing device has: a first divisional photosensing device for dividing a first region including both edge portions in said radial direction of said return light, in two divided areas in said radial direction; a second divisional photosensing device for receiving a second region including both edge portions in a direction which perpendicularly crosses said radial direction of said return light, in two divided areas in said radial direction; and a third divisional photosensing device for receiving a third region including an almost center portion of said return light, in two divided areas in said radial direction. | 12-17-2009 |
20100027086 | LIGHT DEFLECTING DEVICE AND HOLOGRAM DEVICE - A light deflecting device is a light deflecting device for deflecting an incident light beam and has: a coarse motion light deflecting device which has an optical system having at least two conjugate points on an optical axis and deflects the light beam which has passed through one conjugate point and has entered the optical system as an output light beam which passes through the other conjugate point and has a deflection angle with respect to the optical axis while changing its transmitting direction; and a fine motion light deflecting device which is arranged in the optical system, applies a deflection to the incident light beam, and changes the deflection angle of the output light beam to a second deflection angle different from the deflection angle for a predetermined time. | 02-04-2010 |
20100046349 | FABRICATION METHOD OF MULTILAYER OPTICAL RECORD MEDIUM AND RECORDING APPARATUS FOR MULTILAYERED OPTICAL RECORD MEDIUM - A fabrication method of a multilayer optical recording medium having a plurality of recording layers, comprises a step of preparing an optical recording medium having at least one record area; a write-position mark generating step of recording write-position marks in the record area beforehand; a step of preparing an optical system including a common objective lens to focus a data recording beam and a position mark recording beam on different positions in a thickness direction of the record area; a first data writing step of writing data between the write-position marks with following the write-position marks by the data recording beam; a position mark recording step of, in parallel with the first data writing step, recording new write-position marks in the record area by the position mark recording beam; and a second data writing step of writing data between the new write-position marks with following the new write-position marks by the data recording beam. | 02-25-2010 |
20100085859 | HOLOGRAM RECORDING AND REPRODUCING APPARATUS - A laser beam emitted from a laser light source is divided into two laser beams, a 2-dimensional spatial modulation is performed to one of the two divided laser beams based on recording information, the modulated laser beam is projected as signal light onto a recording medium, the other laser beam is projected as reference light onto the recording medium, and the recording information is recorded onto the recording medium. The recording information recorded on the recording medium is reproduced based on the laser beam transmitted through or reflected by the recording medium. An optical system includes: a rotatable mirror portion for guiding the reference light to the recording medium at an angle according to the direction of its reflecting surface; a vibration proofing member coupled with a rear surface of the mirror portion; and a driving mechanism which decides an angle position of the mirror portion and is coupled with the mirror portion. | 04-08-2010 |
20100220576 | OPTICAL PICKUP DEVICE AND INFORMATION RECORDING/REPRODUCTION DEVICE - The present invention makes possible a compact optical pickup device that eliminates effects due to the position where a sub beam is projected during tracking compensation, and provides for stable tracking compensation. | 09-02-2010 |
20100232278 | RECORDING AND REPRODUCING METHOD, RECORDING MEDIUM, AND RECORDING AND REPRODUCING APPARATUS - A recording method which optically records two-dimensional data including a positioning mark and data area in a recording medium. In this method, the state of the positioning mark is changed from a first state to at least one second state different from the first state every given number of recording times of such two-dimensional data. | 09-16-2010 |