Abstract: 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.

Abstract: 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.

Abstract: A method for compensating the coma aberration in a pickup of a recording and reproducing device that records or reproduces data on or from an optical disc using the pickup is provided. The method includes a first coma aberration compensating step to compensate coma aberration in a body of an optical system including an objective lens for emitting a light beam to an optical disc including a plurality of recording layers and a second coma aberration compensating step to compensate coma aberration caused by relative inclination of the optical system with respect to the optical disc.

Abstract: A method for compensating the coma aberration in a pickup of a recording and reproducing device that records or reproduces data on or from an optical disc using the pickup is provided. The method includes a first coma aberration compensating step to compensate coma aberration in a body of an optical system including an objective lens for emitting a light beam to an optical disc including a plurality of recording layers and a second coma aberration compensating step to compensate coma aberration caused by relative inclination of the optical system with respect to the optical disc.

Abstract: An image display system according to the present invention includes a camera that shoots a background, a monitor that displays a shot background image, and an optical lens arranged on a display surface of the monitor. An imaginary image, obtained due to presence of the optical lens, of the monitor image is made to substantially match with a background surface, so that observers viewing the background through the monitor can recognize that the monitor image and the background look continuous. As a result, the image display system and the image display method that can cause the observers viewing the background through the monitor to recognize that the monitor image and the background look continuous are provided.

Abstract: In an information display apparatus such as a head-up display, while safety is being secured, visibility from a user is improved. Image data having an object such as an arrow showing an advancing direction or a road sign drawn on it are generated as information to be given to the user by a display information generating section 12 and is output to a projector 13. When a light beam R1 corresponding to the image data is emitted from the projector 13 to a combiner 14, reflected light of the light beam R1 and transmitted light of external light R2 are combined in the combiner 14, so as to be viewed by the user.

Abstract: 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.

Abstract: 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. The invention adjusts the positions where the sub beams are shone onto the surface of an optical disc DK by changing the angle of a diffraction grating 211 that is mounted inside an optical pickup. When performing adjustment, the angle of the diffraction grating 211 is performed in three stages: (i) rough adjustment, (ii) initial fine adjustment and (iii) continuous fine adjustment.

Abstract: 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. An optical pickup device 200 of an embodiment of the present invention has a diffraction grating 230 of a special shape including predetermined grooves and two kinds of lattice grooves arranged at a pitch determined on the basis of a pitch of grooves formed in the surface of an optical disk 50, numerical aperture, wavelength of a light beam, and effective diameter of the light beam applied on the optical disk 50.

Abstract: 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. A diffraction grating 12 in the optical pickup device PU gives an astigmatism to a sub beam (either of ±1-dimensional light), and shines that sub beam onto an optical disc DK. Also, a tracking error signal Ste is obtained by subtracting a push-pull signal PPsub that corresponds to a sub beam from a push-pull signal PPmain that corresponds to a main beam (0-dimensional light), and tracking compensation is performed based on that tracking error signal Ste.

Abstract: A pickup device which, focusing a ray bundle on a track of a recording surface of an optical recording medium to form a light spot, comprises a detection optical system including a photo detector to receive return light reflected from the light spot via an objective lens and perform photoelectric conversion. The photo detector has at least two photoreceptor sections positioned axis-symmetrical with respect to a detection-side division line extending through an optical axis of the return light and parallel to the track. A dividing element placed in an optical path between the photo detector and the objective lens includes at least two inner divided areas positioned axis-symmetrical with respect to a deflection-side division line extending through the optical axis of the return light and parallel to the track, and at least two outer divided areas positioned sandwiching the inner divided areas and axis-symmetrical with respect to the deflection-side division line.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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. An optical pickup device 200 of an embodiment of the present invention has a diffraction grating 230 of a special shape including predetermined grooves and two kinds of lattice grooves arranged at a pitch determined on the basis of a pitch of grooves formed in the surface of an optical disk 50, numerical aperture, wavelength of a light beam, and effective diameter of the light beam applied on the optical disk 50.

Abstract: 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.

Abstract: 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. The invention adjusts the positions where the sub beams are shone onto the surface of an optical disc DK by changing the angle of a diffraction grating 211 that is mounted inside an optical pickup. When performing adjustment, the angle of the diffraction grating 211 is performed in three stages: (i) rough adjustment, (ii) initial fine adjustment and (iii) continuous fine adjustment.

Abstract: 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. An optical pickup PU for emitting a light beam B to an optical disk DK in which recording tracks having a land/groove structure are formed and receiving reflection light of the emitted light beam B, has: a liquid crystal panel 3 for correcting astigmatism included in light beam B by a cause peculiar to an optical system as a component of the optical pickup PU in a state where tracking servo is on, and correcting the astigmatism and a fundamental track crossing noise in a state where the tracking servo is off, and a liquid crystal panel control unit 8 for operating a liquid crystal panel 3 while making a switch in accordance with the state of the tracking servo.

Abstract: In an information display apparatus such as a head-up display, while safety is being secured, visibility from a user is improved. Image data having an object such as an arrow showing an advancing direction or a road sign drawn on it are generated as information to be given to the user by a display information generating section 12 and is output to a projector 13. When a light beam R1 corresponding to the image data is emitted from the projector 13 to a combiner 14, reflected light of the light beam R1 and transmitted light of external light R2 are combined in the combiner 14, so as to be viewed by the user.

Abstract: An image display system includes a camera that shoots a background, a monitor that displays a shot background image, and an optical lens arranged between a display surface of the monitor and an observer. An imaginary image, obtained due to presence of the optical lens, of the monitor image is made to substantially match with a background surface. As a result, when the observer views the background through the monitor, the monitor image and the background look continuous to him.