Abstract: An optical pickup head (100) for a high density recording and/or reproducing device compatible with first and second optical recording media. The pickup head includes a first light source (11) emitting first light beams with a first wavelength, a second light source (12) emitting second light beams with a second wavelength greater than the first wavelength, a prism unit (3), a collimating lens (4) located beside the prism unit for collimating incident first and second light beams, and an objective lens (7) for receiving the first and second light beams and transmitting the first and second laser beams to the first and second recording media respectively. The prism unit includes a first portion facing the first light source and receiving the first light beams, a second portion facing the second light source and receiving the second light beams, and an aspherical surface for the second light beams to pass therethrough.

Abstract: Beams of light emitted from a light source are incident on a polarizer. The direction of a transmission axis of the polarizer can be adjusted in advance such that the polarizer transmits P polarized light, and S polarized light is attenuated. Beams of light transmitted through a diffracting device and a collimator lens for incidence on a beam splitter are made up substantially only by P polarized light. Part of the beams of light, which is reflected on the beam splitter, is incident on a photodetector for feedback control of outputs from the light source. Since S polarized light is attenuated by the polarizer, only P polarized light is incident on the photodetector. Consequently, if the quantity of emitted laser beams changes, a ratio between the quantity of light for record and reproduction and the quantity of light for APC remains substantially constant, thereby increasing accuracy of detecting the intensity of laser beams, to avoid errors in record and reproduction.

Abstract: An optical disc device and a method are for scanning a medium via a beam of radiation while focusing the beam, in particular for scribing a visible label on a record carrier that has a label side provided with a radiation sensitive layer for creating the visible label. The device has a head for providing the beam and a detector for generating a detector signal (CA) from radiation reflected from the medium. A focus system is provided for generating a focus control signal for focusing the beam of radiation to a spot on the medium. A focus excitation signal (505) is added to the focus control signal and a focus correction signal is generated based on detecting a center of gravity in the detector signal, the weight of the detector signal being determined in dependance of the focus excitation signal.

Abstract: In an optical head device having a laser light source, an output adjusting member for adjusting the output of laser light emitted from the laser light source and a frame for supporting the laser light source and the output adjusting member, the output adjusting member has an adjusting circuit board for adjusting an electrical resistance value, and a plurality of circuits on which chip resistors and short lands are connected to one another in parallel are connected in series.

Abstract: A light blocking unit includes a plate-like member which is different from a housing member, and a light blocking portion formed on the plate-like member, for blocking light. A light detector has a light receiving portion for receiving light which is partitioned into four divided regions, by a Y-axis-wise parting line and an X-axis-wise parting line in X-Y coordinates, and outputs photoelectric output signals for the respective divided regions in accordance with intensity of the light received by the respective divided regions of the light receiving portion. Of light beams emitted from a polarization beam splitter, a part of the light beams are blocked by the light blocking unit while the other part of the light beams are not blocked and thus emitted to the light detector excluding a region defined by two sides parallel to the parting lines.

Abstract: The present invention relates to a beam shaper and to an apparatus for reading from and/or writing to optical storage media using in such a beam shaper. According to the invention, a beam shaper for generating a first shaped light beam from an incoming light beam has a beam shaping element with an optical property that varies spatially over the profile of the incoming light beam.

Abstract: In an optical disk, a substrate has main data recorded in the form of a combination of pits and lands on one side thereof, and at least a reflective layer and cover layer are stacked on the substrate to cover the pits and lands on the substrate. To the optical disk, sub data is recorded in the form of marks formed by irradiating writing-power laser light to the reflective layer. The marks are formed so that reading signal level will be raised where the marks are formed while it will be lowered where the marks are formed in a counterfeit disk produced based on an authenticated disk, namely, the reading signal level where the marks are formed is different in polarity between in the authenticated and counterfeit disks. Further, in a player for the optical disk, discrimination is made between the authenticated and counterfeit disks by detecting the sub data recorded in the optical disk and judging whether the value of the detected sub data has been read at a correct polarity.

Abstract: To provide an optical information-recording medium that can easily record information at high density and has excellent durability at low cost. The optical information-recording medium includes a diamond-like carbon (DLC) layer (2) deposited on a substrate (1), in which information is recorded on the optical information-recording medium by irradiating recording spot regions selected from a plurality of recording spot regions with an energy beam (5) to increase the refractive index of the DLC layer (2) in the irradiated recording spot regions.

Abstract: In an optical information reproducing method for reproducing information from an optical information recording medium of land/groove and low-to-high recording system having a substrate (1) and a recording layer (2), light having a wavelength of 390 to 440 nm is projected to the recording layer (2) through the substrate (1) with use of an objective lens having a numerical aperture of 0.65 to thereby reproduce the information, wherein assuming that a wavelength of the light is ? and an index of refraction of the substrate (1) in the wavelength ? is ns, a depth D of a portion (G?) of the recording layer (2) corresponding to the groove (G) with respect to a portion (L?) of the recording layer (2) corresponding to the land (L) satisfies a relation of ?/5.8 ns?D??/5 ns.

Abstract: According to one embodiment, an APC photodetector accepts a light beam branched from a light beam toward a recording medium by a branching mirror and detects intensity of a light beam supplied from a light source, a light quantity adjusting element adjusts the intensity of the light beam, and the intensity of the light beam incident to the APC photodetector is changed in a continuous manner or a stepwise manner by the light quantity adjusting element. Therefore, when the single APC photodetector detects recording and reproducing light beams, the recording and reproducing light beams can fall within a dynamic range of the APC photodetector.

Abstract: In a confocal optical system provided with a light source 13, a first focusing means 14, a second focusing means 16, an aperture 17, and a detector 18, the detector has plural light reception regions. A position displacement is detected by detecting an intensity distribution of an image caused by a position displacement between the focusing spot of the second focusing means 16 and the aperture 17 by the detector 18, and the position displacement is corrected by controlling the aperture position using driving means 19 and control means 20. Also, a position displacement of the aperture 17 in the optical axis direction is detected and corrected on the basis of a change in output of the detector 18 by oscillating the aperture 17 in the optical axis direction.

Abstract: A very small spot-size light beam forming apparatus of the present invention comprises: a conductive film for generating a surface plasmon when an inputted light is applied thereto: a plurality of nano projections, each connected to the conductive film at one end, for receiving a portion of the surface plasmon, and outputting a plurality of input surface plasmons, respectively, from the other end of each of the plurality of nano projections, the other end of each of the plurality of nano projections having a diameter smaller than a wavelength of the inputted light; a coupling unit, connected to the other end of each of the plurality of nano projections, for receiving and coupling the plurality of input surface plasmons, so as to generate a coupled surface plasmon; and a negative-refractive-index lens, connected to the coupling unit and having a negative refractive index, for receiving a near-field light generated due to the coupled surface plasmon, and collecting the near-field light on a recording surface of

Abstract: An optical disk discriminating method and an optical disk device which can detect reflected rays for making discrimination among kinds of optical disks with high accuracies. By switching a plurality of lasers and moving a spherical aberration corrector while moving an objective lens to cause it to approach or keep away from an optical disk, rays reflected light from the optical disk can be detected with high accuracies. Discrimination among the kinds of a plurality of optical disks can be made on the basis of signals generated from the detected reflected rays. This ensures that the kind of an optical disk can be determined through one operation of sweeping.

Abstract: Provided is a resin composition suitable for an optical element in which the moldability, thermal resistance, mechanical strength, and low birefringence are not impaired, the deterioration is hardly generated although the laser light nearby the UV is used, change in the optical properties during the use are extremely small, particularly the light transmittance is maintained high, and a foreign substance is hardly deposited on a surface of the molded product such as an optical element, also provided is an optical element obtained by molding the resin composition, and an optical pickup device using the optical element. The thermoplastic resin composition contains the polymer having a specific structure and two kinds of specific optical stabilizers in a specific mass ratio among a hindered amine light stabilizer having the molecular weight of 400 to 5,000; the optical element is obtained by molding the thermoplastic resin composition; and the optical pickup device includes the optical element.

Abstract: An optical reading/writing apparatus has an optical head that includes a collimator and a lens. For efficient and reliable focusing control for writing an empty optical disk, calibration of focus offset and spherical aberration is executed by setting a boundary and performing data-reading in an OPC area only with combinations of focus offset and spherical aberration within the boundary. Accordingly, an optimum combination of focus offset and spherical aberration is determined for focusing compensation in subsequent writing operation of the empty disk.

Abstract: An optical information apparatus of the present invention includes: an optical pick-up head including: a light source; a diffraction unit; a condensing unit; a beam splitter; a photodetector; and a tracking error signal generator. An optical recording medium has tracks arranged substantially at a constant pitch. An average of a pitch is tp. When a main beam is placed on the track, a first sub-beam and a second sub-beam are placed between the tracks.

Abstract: An optical element to be arranged in an optical pickup apparatus for conducting information recording and/or reproducing and to converge laser light beams having a plurality of wavelengths including a wavelength of ?1 onto information recording media, includes one or more of optical element main bodies; and an antireflective film which is arranged on at least one surface on the optical element main bodies and on which an optical functional surface is formed, wherein, when the optical functional surface and a first laser beam having the wavelength ?1 makes an angle ?1 in the range of 0°??1?60°, the optical element satisfies |Rp1?Rs1|?2% where Rp1 and Rs1 are respectively P polarized light and S polarized light reflectivities of the first laser light on the optical functional surface.

Abstract: There is provided an optical disc recording/reproduction device capable of accurately performing the focus offset and spherical aberration correction even for an optical disc having no data recorded. The optical disc recording/reproduction device includes: an optical pickup having a spherical aberration corrector for correcting the spherical aberration of an objective lens; and various control units; and can generate a tracking error signal (TE) at least by a push-pull signal by the push-pull method. When an optical disc mounted is in an unrecorded state, the spherical aberration correction amount and the objective lens focus offset amount are adjusted according to the push-pull signal, predetermined data is recorded on the optical disc, and the reproduction signal obtained by the data is used to adjust the spherical aberration correction amount in the spherical aberration corrector of the optical pickup and the focus offset amount of the objective lens.

Abstract: An optical pickup unit includes first and second light sources of first and second wavelengths, respectively, a diachronic element, a phase plate, and an objective lens. One of the first and second light sources is selected so that information recording or reproduction is performed by converging a light beam emitted from the selected one of the first and second light sources on an optical recording medium via the diachronic element, the phase plate, and the objective lens.

Abstract: An optical data storage system for recording and/or reading, using a radiation beam having a wavelength X is described. The radiation beam is focused onto a data storage layer of an optical data storage medium. The medium has a cover layer that is transparent to the focused radiation beam. The cover layer has a thickness h smaller than 5 ?m. A cover layer with thickness variation of substantially less than the focal depth, i.e. 50 nm, eliminates the need of dynamic focus control of the objective which is otherwise required in addition to the gap servo. Further a method of optical recording is described using such an optical data storage system by which a static focus control and spherical aberration correction to accommodate medium-to-medium variance is achieved. The static focus control can be realised by optimising the modulation depth of a known signal, e.g. from a lead-in track.

Abstract: An optical pickup performing recording, reproduction and deletion of information on or from an optical recording medium. The pickup includes light sources for information recording media using a blue wavelength beam, information recording media of DVD family and information recording media of CD family. A single object lens may be used to condense light from any of the light sources. A single aberration correction device may be disposed in a common light path between each of the light sources and the object lens.

Abstract: An optical pickup device comprising a plane-parallel plate beam splitter that reflects a laser beam emitted from a laser beam source, an objective lens that focuses the laser beam from the plane-parallel plate beam splitter so as to irradiate the focused beam into a signal recording medium, a photodetector that receives the laser beam reflected and returned from the signal recording medium through the beam splitter, the photodetector having light receiving regions each of which is divided at least into four parts by two dividing lines that intersect each other at right angle, a first plane-parallel plate disposed between the beam splitter and the photodetector, the first plane-parallel plate being tilted in the direction rotated ?/2 radians around the optical axis with respect to the beam splitter, and a second plane-parallel plate disposed between the beam splitter and the photodetector, the second plane-parallel plate being tilted in the direction of rotation around the optic axis such that the direction of

Abstract: An objective optical element of an optical pickup apparatus has a magnification m1 satisfying the following formula for a light flux of the wavelength ?1: ? 1/7?m1?? 1/25 and |m1|<|M1, where M1 is an optical system magnification from the first light source to the first optical information recording medium for a light flux of the wavelength ?1. The objective optical element comprises a common region and an exclusive region. The exclusive region includes an exclusive diffractive structure having a function to suppress an increase of spherical aberration due to a raise of atmospheric temperature. A light flux of a wavelength ?2 having passed through the exclusive diffractive structure intersects with the optical axis at a position different from the position of the converged light spot formed on the information recording plane of the second optical information recording medium.

Abstract: An optical pickup actuator for low building height includes a suspended lensholder (101) with a lenssystem (102), focusing (106a, 106b, 106c 106d) and tracking coils (109) and magnets (107a, 107b, 107c) for cooperation with the focusing and tracking coils. The focusing and tracking coils may be arranged for tilting the lensholder in the actuator. The lowest entrance position for a radiation beam to enter a beam entrance (113) at a side of the actuator is not determined by the height and location of the coils.

Abstract: An optical pickup apparatus including a swing arm pivotably installed in a tracking direction with respect to a disc, and an optical pickup unit supported by the swing arm and driven in a focusing direction, wherein the optical pickup unit includes a laser diode, an objective lens to focus light emitted from the laser diode on a recording surface of the disc, and a heat sink plate to dissipate heat generated from the laser diode, wherein the heat sink plate is provided close to the disc so as to be directly exposed to wind generated during rotation of the disc.

Abstract: An optical pickup apparatus for conducting recording and/or reproducing information of an optical information recording medium, comprises a light source; a converging optical system having an objective lens; and a photo-detector. The converging optical system comprises a plastic lens and a spherical aberration deviation correcting element to correct deviation of a spherical aberration of the converging optical system. A numerical aperature of the objective lens at an image-side is 0.65 or more.

Abstract: An optical device comprises a wavefront modifier for introducing a wavefront modification in a radiation beam. The wavefront modifier comprises a first optical element (110) and a second optical element (111). The two optical elements are arranged in such a way that a suitable alternative movement of the first optical element leads to a translation of the second optical element by means of a stick-slip effect. This allows obtaining the desired mutual displacement between the two optical elements.

Abstract: An optical pick-up unit is suitable for scanning a first type of record carrier having a first information density and at least a second type of record carrier, the second type of record carrier having a second information density different from the first information density. The optical pick-up unit comprises a first radiation source (16, 86) for emitting a first diverging radiation beam (24) for scanning the first type of record carrier, and at least a second radiation source (48, 96) for emitting a second radiation beam (50) for scanning the second type of record carrier. The optical pick-up unit also comprises a first beam splitter (58, 93, 104) for combining the first radiation beam and the second radiation beam on a common optical path. The first beam splitter is a plane-parallel plate-type beam splitter. A correcting element (20, 22, 72) for astigmatism and coma correction is arranged between the first radiation source and the first beam splitter.

Abstract: A photodetection device is provided with a photoelectric converter portion that converts light to electric current, an electrical current/voltage converter portion, including a feedback circuit that returns at least part of the output to the input side, that converts the electrical current received from the photoelectric converter portion to a voltage corresponding to the resistance value of the feedback circuit and outputs the voltage, where the feedback circuit includes a first MOS transistor that allows the resistance value to be varied in accordance with the gate voltage.

Abstract: An optical pickup includes: a slide base, having: a first surface; and a second surface; a first substrate fixed to the first surface; a standing frame disposed on the second surface; a second substrate facing the standing frame; a laser diode operable to emit a laser beam to the disk and disposed in the standing frame; an optical, element supported by the second substrate and adapted to receive a reflected beam; a flexible flat cable. The flexible flat cable is bent so that one end portion of the flexible flat cable is connected to the second substrate. A curved portion is formed with a slit elongated in a longitudinal direction of the flexible flat cable and defines an outer portion and an inner portion. A width of the inner portion is narrower than a width of the outer portion.

Abstract: In a magnetic recording device, a semiconductor laser (LD) is disposed at a position with a predetermined distance from a swing arm having a slider. The laser beam output from the LD is irradiated, via a beam converter and a mirror, to a spherical aberration lens that generates spherical aberration. The laser beam transmitted through the spherical aberration lens is directed to a light incident opening of the slider at a constant angle (perpendicularly), and then to a position of a recording medium at which information is recorded, thereby performing thermal assist at the magnetic recording time.

Abstract: Disclosed herein is an optical lens suitable for a near-field optical recording/reproducing system. A condenser lens, optical pickup, and optical recording/reproducing apparatus each using this optical lens are also disclosed. This optical lens is formed from an SiC single crystal having a cubic structure. The condenser lens includes a first optical lens and a second optical lens arranged in this order from an objective surface, and at least the first optical lens is formed from an SiC single crystal having a cubic structure. The optical pickup includes a light source and a condenser lens for converging light emitted from the light source to form a beam spot. This condenser lens has the same configuration as the above. The optical recording/reproducing apparatus includes this optical pickup.

Abstract: It is an object to provide filters for optical recording media capable of preventing diffuse reflection of informing and reference lights from reflective films of optical recording media and inhibiting noise therefrom without shifting the selective reflection wavelength even when the incident angle is variable, optical recording media of hologram type having the filters and capable of recording images with higher density over the prior art, methods for producing the optical recording media with higher efficiency and lower cost, and also optical recording methods and optical reproducing methods that utilize the optical recording media. In order to attain the object, provided are filters for optical recording medium, comprising a colorant-containing layer, wherein the colorant-containing layer comprises at least one of pigments and dyes, and a cholesteric liquid crystal layer is disposed on the colorant-containing layer, and also optical recording media of hologram type comprising the filter.

Abstract: Theft, distribution, and piracy of digital content on optical media (software, video, audio, e-books, any content of any kind that is digitally stored and distributed) is often accomplished by copying it directly to another disc using commonly available copy tools and recordable optical media, or the copying of media to another mass manufactured disc. Methods which cause—the copy process to become lengthy and inconvenient, or which produce copies that are significantly measurably different from the original and therefore be recognizable as copies, deter or prevent an unauthorized individual from making copies. This is accomplished by modifying the optical path of an optical medium to include regions of selective distortion. This, in turn, modifies the read operation of the data in the regions, which can be used to identify and authenticate the medium.

Abstract: The present invention relates to an optical scanner system for scanning of an optical sound track with a beam of light, comprising a light emitter for emission of a light beam, a device for scanning the light beam across an optical sound track, the light beam forming a scanning spot on the optical sound track, an optical detector for detection of the light beam upon interaction of the light beam with the optical sound track and generating an electronic signal representing the sound recorded in the optical sound track.

Abstract: A focusing controller and the method thereof for an optical disk drive. The focusing controller includes a filter, a coupler and a focus compensator. The filter filters out a high-frequency component of the track error signal and derives an adjusted signal, while the coupler eliminates the adjustment signal from the focusing error signal so as to generate a coupled signal. The focus compensator generates a focus control signal used for controlling a position of the pick up head of the optical disk drive according to the coupled signal during a focusing operation.

Abstract: In an optical scanning device (10) capable of scanning an information plane of an optical record carrier (5) of different types such as BD, DVD and CD, the diameter of the radiation spot on the detector (7) is dependent on the numerical aperture of the objective system (4) that is used for scanning the record carrier An optimal design of the optical detection system for scanning a BD, result in a small radiation spot for the other types such as DVD and CD.

Abstract: An optical pickup used to record information on and/or reproduce information from an optical recording medium, the optical pickup including an optical module to emit a light beam; and a front photo-detector to monitor power of the light beam; wherein the optical module is coupled to the front photo-detector so that a fixed distance is maintained between the optical module and the front photo-detector.

Abstract: The present invention relates to a method and a corresponding apparatus for recording an information on a recordable optical record carrier (2) by irradiation of a light beam through optical means (3-7) onto said record carrier (2) for forming marks and lands representing said information along an information recording direction (t). To obtain a higher recording density, and thus higher data capacity, it is proposed according to the present invention to reduce the numerical aperture of the optical means (3-7) in the direction (r) orthogonal to the information recording direction (t), which is the radial direction for an optical disc, during recording of information to obtain a light beam having a substantially oval spot profile having a shorter axis in the information recording direction (t), i.e. the tangential direction for an optical disc, compared to the direction (r) orthogonal that to, i.e. the radial direction.

Abstract: When the DVD provided with the DVD substrate 2 having thickness t2 of 0.6 mm is installed in the optical disc apparatus, the light beam 4 having wavelength ?1=655 nm is used as luminous flux of numerical aperture NA=0.63 to be condensed on the information surface 2a on the DVD substrate 2. When the CD provided with the CD substrate 3 having thickness t2 of 1.2 mm is installed in the optical disc apparatus, the light beam 5 having wavelength ?2=790 nm is effectively used as luminous flux of approximate numerical aperture NA=0.45 to be condensed on the information surface 3a on the DVD substrate 3. The wavefront aberration caused by a thickness difference between the DVD substrate 2 and CD substrate 3 is canceled out by the chromatic aberration caused by a wavelength difference between the light beams 4 and 5. Therefore, in spite of the difference in the transparent substrates, the light beams are suitably condensed respectively on the information surface 2a and 3a.

Abstract: A semiconductor laser device includes: a semiconductor laser chip which is composed of a semiconductor substrate and a plurality of semiconductor layers stacked on an element formation face of the semiconductor substrate and which outputs an irradiation light for irradiating an optical disk; and a light receiving element which receives the irradiation light reflected by the optical disk as a feedback light. The semiconductor laser chip includes on one face thereof an electrode facing an optical element and is fixed in a package so that at least one of sub-beams reflected by the optical disk is incident on the one face. A chip exposing portion for exposing a region of the one face where the sub-beam is incident is formed in the electrode.

Abstract: There is provided an objective lens used for a plurality of types of optical discs having a front surface and a rear surface, each of which includes an inner region and an outer region. The outer region has a surface shape which suppresses a coma caused when a beam used for a first optical disc is incident thereon obliquely with respect to an optical axis of the objective lens. The inner region is configured such that, at a boundary position between the inner region and the outer region, the coma caused when a beam used for a second optical disc is incident on the inner region obliquely at a first angle with respect to the optical axis is less than the coma caused when the beam used for the second optical disc is incident on the outer region obliquely at the first angle with respect to the optical axis. Further, an inclination ?2A of the inner region and an inclination ?2B of the outer region of the rear surface satisfy a condition: ?2.5<?2B??2A<0.0.

Abstract: The present invention relates to an optical system for reproducing and/or recording on optical record carrier. The system includes light providing means for providing at least: 1) a main beam for reading information, and 2) a plurality of auxiliary beams for radial tracking; a first (A), a second (B) and a third (C) auxiliary beam. The optical record carrier has readable effects arranged in tracks (2, 12) in one or more spiral(s), the spiral(s) being separated by one or more guard band(s) (5, 15). The optical system performs radial tracking from the reflected light of 1) the first auxiliary beam (A), the first auxiliary beam being positioned in a first guard band, and 2) the second (B) and third auxiliary beam (C). The second auxiliary beam is positioned on a first track (I), and the third auxiliary beam (C) is positioned on a second track (II) and on opposite side of the first guard band (5, 15) relative to the second auxiliary beam (B).

Abstract: A focusing lens for an LED is provided.

Abstract: An optical scanning device (1) includes a radiation source (7), a detector (23) and a beam splitter (9). The radiation source (7) provides an incident radiation beam (4, 20) along a first optical path (19a) for scanning an information layer (2) of an optical record carrier (3). The detector (23) detects at least a portion of the radiation beam (22) reflected from the optical record carrier (3). The beam splitter (9) transmits the incident radiation beam (4) received from the radiation source along the first optical path (19a) towards the optical record carrier. The beam splitter (9) also transmits the reflected beam (22) received from the optical record carrier (3) along a second, different optical path (19b) towards the detector. The optical scanning device further includes a beam-deflecting element (30; 130; 230; 330; 630; 830; 930) positioned on the second optical path (19b) between the beam splitter (9) and the detector (23).

Abstract: In an optical disk apparatus having an exclusive RF detector plane mounted therefore, as a method of obtaining a synthesized readout signal based on band-synthesis is used in order to obtain a readout signal having a good S/N ratio, a waveform distortion easily caused by a delay time difference or a sensitivity difference in the playback at higher speeds can be prevented. In order to correct the delay time difference or a sensitivity error in two channels of RF signals to be band-synthesized according to the selection of the sensitivity or playback speed, a delay time controller, a sensitivity controller, and a selector for selecting a combination method are engaged. An information holder for such control or selection is also provided.

Abstract: An optical pickup apparatus for reproducing information from an optical disk, includes: a semiconductor laser applying a beam to an optical disk having two recording layers through an objective lens; and a light receiving device to which light reflected from the optical disk is directed through the objective lens and a beam splitting device, wherein: the beam splitting device has two first light receiving areas for detecting a push-pull signal and a second light receiving area for detecting a focus error signal, and a configuration is provided such that the center of the optical axis of the reflected light in the beam splitting device is made to lie within the second light receiving area for detecting the focus error signal.

Abstract: Plural grooves or lands formed in an information recording carrier include at least a wobbling region and data is recorded wobblingly in this wobbling region by phase shift modulation while recorded digitally with a single or multiple waves as a channel bit.

Abstract: A pickup for a magneto-optical recording medium is provided, which improves quality of reproduced signals by eliminating a phase difference between the polarizations and is capable of coping with magneto-optical recording media of different recording/reproducing systems. A return light beam of light reflected by a magneto-optical recording medium is polarized and separated into ± first-order diffracted lights through a light-branching diffraction element provided between a light source and an objective lens. The ± first-order diffracted lights are compensated for their phases through first and second phase compensation elements so that there is no phase difference between the polarizations, and are, further, polarized and separated through the first and second polarization/separation elements, and are received by first and second light detectors.

Abstract: A device (1) for scanning an optical disc (6), the disc (6) comprising substantially parallel data tracks (10). The device (1) comprises an optical unit for creating track light spots (12) on the data tracks (10) and a plurality of detector light spots on a plurality of signal detectors. The device further comprises a focus error unit for with a beam manipulating element (21, 22, 22a, 92) for providing for at least one of the reflected beams a first optical path (24) to a first segmented detector (8a) and a second optical path (25) to a second segmented detector (8b).