Patent application number | Description | Published |
20090073825 | Optical pick-up, aberration correcting method, optical pickup program, information recording device and method, information recording program, information reproducing device and method, information reproducing program, and information recording medium - The invention is to provide an optical pickup capable of performing a track search operation accurately by reducing noise occurring in a focus servo system during the track search operation and also accurately recording/reproducing information to/from an optical disk. | 03-19-2009 |
20090092029 | OPTICAL PICKUP DEVICE AND INFORMATION RECORDING/REPRODUCTION DEVICE - The present invention makes it possible to accurately and adequately adjust the position where sub beams are shone when performing tracking correction or CTC using three beams. | 04-09-2009 |
20090103417 | OPTICAL PICKUP DEVICE AND INFORMATION RECORDING/REPRODUCING APPARATUS - There are obtainable reliable and proper tracking correction and CTC even when fluctuations occur in an irradiation position of a sub-beam in a track at the time of performing tracking correction and CTC using three beams. Five beams (a main beam, sub-beams inA and inB, and sub-beams outA and outB) are generated. Reflection beams of the five beams are received, and a differential push pull signal DPPin corresponding to the sub-beams “in” as ± first-order beams and a differential push pull signal DPPout corresponding to the sub-beams “out” as ± second-order beams are generated. By assigning weights to the differential push pull signals DPPin and DPPout and computing the sum of the weighted signals, a tracking error signal Ste having an amplitude value which can perform tracking correction is generated. | 04-23-2009 |
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 |
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 |
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 |
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 |