Entries |
Document | Title | Date |
20080205243 | Optical Head Apparatus and Optical Information Recording or Reproducing Apparatus Having the Same - An object of the present invention is to provide an optical head apparatus having a high signal to noise ratio in an RF signal in a simple circuit configuration, and an optical information recording or reproducing apparatus that uses it. The optical head apparatus includes a light source, an objective lens configured to focus an output light beam from the light source onto a disc-shaped optical recording medium, and a light detecting unit configured to receive a reflection light beam from the optical recording medium, and further includes an optical diffraction element configured to separate said reflection light beam into a first light beam group and a second light beam group, wherein the optical diffraction element generates the first light beam group from an entire section region of the reflection light beam and said second light beam group from at least a part of the section region of the reflection light beam. The light detector receives the first light beam group and the second light beam group by different light receiving sections, in order to detect a track error signal used for a track servo and a radial tilt signal indicating the radial tilt of the optical recording medium. | 08-28-2008 |
20080212451 | Optical Sound Track Scanner System - 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. | 09-04-2008 |
20080219130 | Methods and Apparatus for Formatting and Tracking Information for Three-Dimensional Storage Medium - A formatter for inscription of marks on to a 3D translucent optical medium to enable recording and retrieval of information from the medium, includes a clamping mechanism to hold the media, and at least one optical unit calibrated to focus at least one diffraction limited spot within the medium at a respective depth therein. At least one light source is optimized for the inscription of marks, and at least one actuator moves the spot relative to the medium. | 09-11-2008 |
20080232223 | OPTICAL PICKUP APPARATUS AND BEAM SPLITTER - There is provided an optical pickup apparatus and a beam splitter which are capable of suppressing an adverse effect resulting from light reflected by a non-light-condensed layer that is different from a light-condensed layer. In respective TES light-receiving sections, interposed light-receiving elements are disposed so as to be adjacent to first sub beam-receiving elements. The interposed light-receiving elements are disposed away from both of positions where a main beam reflected by a light-condensing recording layer is condensed and where respective sub beams reflected by the light-condensing recording layer are condensed, and disposed so as to be adjacent to the first sub beam-receiving elements. The interposed light-receiving elements receive the main beam reflected by a non-light-condensing recording layer In a compensating section, results of light received by the first sub beam-receiving elements are compensated based on results of light received by the interposed light-receiving elements. | 09-25-2008 |
20080279082 | OPTICAL PICKUP, RECORDING/REPRODUCING APPARATUS AND RECORDING/REPRODUCING METHOD - A recording medium, a recording/reproducing apparatus, and a recording/reproducing method are disclosed. The apparatus uses the number of record layers contained in a recording medium and a multi-wavelength light source including a plurality of optical signals having different wavelengths, and irradiates an optical signal emitted from a light source on each recording medium according to wavelengths of the light beams. As a result, the apparatus can effectively gain access to the recording medium including a plurality of record layers, such that it can simultaneously record/reproduce data in/from the recording medium. | 11-13-2008 |
20090022036 | DIFFRACTION OPTICAL ELEMENT, MOLDING DIE FOR THE OPTICAL ELEMENT AND MANUFACTURING METHOD THEREOF - A diffraction optical element is provided to reduce harmful lights and also suppress deterioration in the optical characteristics of the element. The diffraction optical element | 01-22-2009 |
20090028035 | OPTICAL HEAD DEVICE AND OPTICAL INFORMATION PROCESSING DEVICE - An optical head device according to the present invention includes a splitting section for splitting a light beam having been reflected from an optical storage medium. The splitting section includes: a first main region transmitting a first interfering portion; a second interfering portion transmitting a second main region; and first and second sub-regions through which the first interfering portion is transmitted with a lower rate than in the first main region and through which the second interfering portion is transmitted with a lower rate than in the second main region. The splitting section splits the reflected light beam into: a first main light beam transmitted through the first main region; a second main light beam transmitted through the second main region; a first sub-light beam transmitted through the first sub-region; and a second sub-light beam transmitted through the second sub-region. The splitting section further includes a swapping section for swapping a portion of the first sub-light beam with a portion of the second sub-light beam. | 01-29-2009 |
20090034398 | OBJECT LENS, OPTICAL PICKUP, AND OPTICAL DISC DEVICE - An optical pickup includes: a first emitting unit to emit an optical beam of a first wavelength; a second emitting unit to emit an optical beam of a second wavelength; a third emitting unit to emit an optical beam of a third wavelength; an object lens to condense optical beams emitted from the first through third emitting units onto a signal recording face of an optical disc; and a diffraction unit provided on one face of an optical element or the object lens positioned on the optical path of the optical beams of the first through third wavelengths; wherein the diffraction unit includes a generally circular first diffraction region provided on the innermost perimeter, a ring zone shaped second diffraction region provided on the outer side of the first diffraction region, and a ring zone shaped third diffraction region provided on the outer side of the second diffraction region. | 02-05-2009 |
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 |
20090097380 | OPTICAL PICKUP, OPTICAL DISK DEVICE, COMPUTER AND OPTICAL DISK RECORDER - A diffraction grating is constituted such that directions of diffraction are disposed asymmetrically with respect to the optical axis, by causing light subjected to aperture restriction to have a difference of one half wavelength in the optical path length by making use of the fact that the difference in the optical path length experienced by the light passing through a diffraction element varies depending on the wavelength. With this constitution of the diffraction grating, aperture restriction is applied to both the light focused on an optical disk and the light reflected from the optical disk, thereby achieving an optical pickup that is capable of recording/reproducing information on/from optical disks of different types by using a single objective lens. The optical pickup prevents unnecessary light from entering a photodetector and enables the production of diffraction elements at a low cost. | 04-16-2009 |
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 |
20090129236 | OPTICAL PICKUP DEVICE - An optical pickup device includes a diffraction grating for separating laser light into a main beam and two sub beams, a photodetector having a sensor pattern for receiving the main beam and the sub beams reflected on a recording medium having multiple laminated recording layers respectively individually, and a diffraction element for positioning the main beam and the sub beams reflected on a targeted recording layer to be irradiated on the sensor pattern, and diffracting the main beam and the sub beams reflected on a recording layer other than the targeted recording layer to be irradiated in such a manner that the main beam and the sub beams are not overlapped with each other on the sensor pattern. | 05-21-2009 |
20090135705 | OPTICAL PICKUP AND OPTICAL DISC DEVICE - An optical pickup for performing recording and/or playback of information by selectively irradiating the corresponding wavelength optical beam to first through third optical discs having a protection layer with different thickness, includes emission units for emitting first-wavelength through third-wavelength optical beams corresponding to the respective optical discs respectively, a condensing optical device for condensing each wavelength optical beam on an optical disc signal recording face, a divergence angle transformation device, which can be moved in the optical axis direction, for transforming the divergence angle of each wavelength optical beam according to the moved position in the optical axis direction so as to obtain a predetermined divergence angle, and a detector having a common light receiving unit for receiving each wavelength optical beam separated by an optical path separating unit and returned, with the condensing optical device condensing each wavelength optical beam on the corresponding optical disc signal recording face appropriately. | 05-28-2009 |
20090147658 | OPTICAL HEAD AND OPTICAL INFORMATION RECORDER/REPRODUCER EMPLOYING IT - To provide an optical head capable of detecting tilt with high sensitivity for two kinds of optical recording media having different groove pitches, and to provide an optical information recording/reproducing device, diffraction optical elements split emitted light from a light source into a main beam, a first sub-beam (diffracted light from a region of the diffraction optical element, and a second sub-beam (diffracted light from a region of the diffraction optical element). The region of the diffraction optical element has a diameter larger than that of the region of the diffraction optical element. A push-pull signal by the first sub-beam under track-servo is employed as a radial tilt error signal for an optical recording medium having a narrow groove pitch, and a push-pull signal by the second sub-beam under track-servo is employed as a radial tilt error signal for an optical recording medium having a wide groove pitch. | 06-11-2009 |
20090154323 | OPTICAL PICKUP DEVICE AND OPTICAL DISC DEVICE - When recording on and/or reproducing from an information recording medium having a plurality of recording layers is performed, there has been a problem in appropriately detecting a control signal at the time of the recording and/or reproducing, since reflected light from a recording layer, which does not undergo the recording and/or reproducing, enters a photodetector concurrently with reflected light from a recording layer which undergoes the recording and/or reproducing. In the present invention, a polarization hologram is used to diffract light outputted from a light source and to generate a main beam, which is a zeroth-order light beam, and a pair of sub beams, which is a positive first-order light beam and a negative first-order light beam each having a polarization direction perpendicular to a polarization direction of the main beam. Accordingly, it is possible to prevent the reflected sub beams from a recording layer, which is a target undergoing recording and/or reproducing, from interfering with the reflected main beam from a recording layer, which is a non-target not undergoing the recording and/or reproducing. Therefore, it is possible to obtain an accurate control signal based on the sub beams, and also possible to realize an optical pickup device having a preferable recording performance. | 06-18-2009 |
20090190457 | Optical head device and optical information reproducing device - The light emitted from a semiconductor laser is divided by a diffractive optical element into three light beams which are 0th-order light as the main beam and ±1st-order diffracted lights as the sub-beams, and the track error signals by the main beam and the sub-beams are detected, respectively, by a differential phase detection method. By the effect of the diffractive optical element, the light intensity distributions of the main beam and the sub-beams become different when making incidence on an objective lens. Therefore, when there is radial tilt in a disk, the phases of the track error signals by the main beam and the sub-beams are shifted with each other. Based on the shift in the phases of the track error signals, radial tilt of the disk is detected. | 07-30-2009 |
20090190458 | DIFFRACTION ELEMENT AND OPTICAL HEAD DEVICE EQUIPPED THEREWITH - A grating portion has a plurality of convex portions provided on at least one principal plane of a transparent substrate having a first layer containing a first transparent material and a second layer containing a second transparent material, and extended in parallel to each other in a first direction as well as periodically arranged in a second direction orthogonal to the first direction. A filling portion fills a third layer containing a third transparent material at least between the plurality of convex portions. Assuming that the change rate of the refractive index with the change of temperature of the first transparent material is α | 07-30-2009 |
20090213716 | Method and apparatus for recording/reproducing data on/from a recording medium - A method and apparatus for recording/reproducing data is disclosed. The apparatus for recording/reproducing data comprises a diffraction element splitting light diffracted or reflected from a recording medium into a main beam and first and second sub beams, the main beam and the first and second sub beams having no interference from one another; a light-receiving part detecting the main beam and the first and second sub beams; and a controller controlling a position of the diffraction element based on at least one light capacity of the detected beams or the detected position. | 08-27-2009 |
20090231981 | OPTICAL PICKUP AND OPTICAL DATA PROCESSING DEVICE USING THE SAME - An optical pickup including a light source, a light focus device, a diffraction element, an optical split element, a ¼ wavelength board, a light reception device and a correction element wherein the correction element is divided into multiple areas in a surface vertical to an optical axis, each area of the multiple areas has a sub-wavelength convexo-concave structure having a pitch equal to or shorter than a wavelength of the outgoing light beam and the sub-wavelength convexo-concave structures of the multiple areas adjacent to each other have groove directions perpendicular to each other, and the filling factors of adjacent areas of the multiple areas are determined to substantially equalize effective refractive indices with regard to the polarization direction of the outgoing beam emitted from the light source and impart a phase difference of π with regard to a polarization direction perpendicular to the polarization direction of the outgoing beam. | 09-17-2009 |
20090268582 | OPTICAL INFORMATION REPRODUCING APPARATUS AND METHOD THEREOF - An optical information reproducing apparatus includes a light-receiving unit that receives a first reproduction light of an information output from a first region of an information recording layer and a second reproduction light of an information output from a second region of the information recording layer, the first region and the second region being formed by dividing the information recording layer with a line segment that intersects a plane of incidence of the reference light and a plane of the information recording layer, and outputs a first reproduction signal that is a reproduction signal of the first region and a second reproduction signal that is a reproduction signal of the second region. | 10-29-2009 |
20090274031 | OPTICAL PICKUP AND INFORMATION DEVICE - An optical pickup for irradiating an information recording medium, such as a DVD, with a laser beam when an information signal is recorded or reproduced, and information equipment provided with the optical pickup. | 11-05-2009 |
20090290475 | OPTICAL PICKUP APPARATUS - An optical pickup apparatus comprising: a diffraction grating configured to diffract laser light from a laser diode so that signals recorded in first and second optical discs are selectively reproduced, thicknesses of protective layers between surfaces and signal recording surfaces of the first and second optical discs being different from each other; a polarization beam splitter configured to divide laser light from the diffraction grating into first and second laser lights whose light amounts are substantially the same; a first objective lens configured to focus the first laser light onto the signal recording surface of the first optical disc; a second objective lens configured to focus the second laser light onto the signal recording surface of the second optical disc; and a photodetector configured to be applied with return lights of the first and second laser lights reflected from the signal recording surfaces of the first and second optical discs. | 11-26-2009 |
20090316562 | Optical Pickup Apparatus - An optical pickup apparatus comprising: a laser-light source that selectively emits first and second laser lights parallel with each other; a diffraction grating that includes a plurality of periodic structures joined to be different in phase from each other in a direction optically corresponding to an optical-disc-tracking direction, and generates 0th-order and ±1st-order-diffracted lights by diffracting the first or second laser light; an objective lens that focuses the 0th-order and ±1st-order-diffracted lights generated from the diffraction grating on the same track of the disc; and a photodetector to which reflected light of the 0th-order and ±1st-order-diffracted lights focused on an optical disc is applied through the objective lens, and which generates a differential-push-pull signal, a direction of a straight line connecting light-emitting points of the first and second laser lights in the laser-light source being inclined relative to the direction optically corresponding to the optical-disc-tracking direction in the diffraction grating. | 12-24-2009 |
20090323501 | OPTICAL PICKUP AND INFORMATION DEVICE - An optical pickup for irradiating an information recording medium, such as a DVD, with a laser beam when an information signal is recorded or reproduced, and information equipment provided with the optical pickup. | 12-31-2009 |
20090323502 | COMPOSITE OPTICAL ELEMENT - The present invention relates to composite optical elements, and particularly to a composite optical element including a first optical component and a second optical component coupled to the first optical component. | 12-31-2009 |
20100014411 | OPTICAL PICKUP DEVICE - A pickup device includes a diffraction grating | 01-21-2010 |
20100034071 | DIFFRACTION GRATING, OPTICAL PICKUP AND OPTICAL DISC DEVICE - Undesired disturbance components leak eventually into various detection signals and reproduction signals as stray optical beams reflected from recording layers other than a reproduction layer overlap with signal beams on a light reception surface of an optical detector and interference occurs between them when an optical disc having multi-layered recording layers is reproduced. A diffraction grating having a specific grating groove pattern is arranged immediately ahead of an optical detector or in a return optical path. Such optical unit averages the disturbance components resulting from interference between a signal beam and a stray beam and can satisfactorily improve influences of leak. | 02-11-2010 |
20100061217 | OPTICAL HEAD UNIT AND OPTICAL INFORMATION RECORDING/REPRODUCING APPARATUS - Semiconductor lasers emit lights having wavelengths of about | 03-11-2010 |
20100067350 | Optical Pickup Apparatus - An optical-pickup apparatus comprising: a laser-light source; a diffraction grating including first-and-second regions of periodic structures different in phase from each other and a third region whose periodic structure is different in phase from the first-and-second regions; an objective lens focusing main-and-sub-luminous fluxes generated by the diffraction grating on the same optical-disc track; and a photodetector to receive reflected light of the main-and-sub-luminous fluxes from an optical disc and output a detection signal for generating main-and-sub-push-pull signals, a relationship between an incident light width in the objective lens corresponding to the third region and pupil diameters of the objective lens corresponding to first-and-second wavelengths of laser lights being adjusted so that a ratio of minimum value to maximum value of a differential-push-pull-signal is at substantially 50% or more and a ratio of sub-push-pull-signal level to main-push-pull-signal level is at substantially 15% or more, in both cases of the laser lights. | 03-18-2010 |
20100118684 | INFORMATION RECORDING AND REPRODUCING DEVICE - An information recording and reproducing device diffracts by a diffracting means ( | 05-13-2010 |
20100124157 | OBJECTIVE LENS AND OPTICAL INFORMATION RECORDING/REPRODUCING APPARATUS - An optical information recording/reproducing apparatus for an optical disc using a light beam having a wavelength of λ including: an objective lens that converges the light beam onto a recording surface of the optical disc and satisfies a condition: | 05-20-2010 |
20100172228 | VOLUMINAL INFORMATION RECORDING MEDIUM, INFORMATION RECORDING APPARATUS, INFORMATION REPRODUCING APPARATUS , AND OPTICAL PICKUP - The present invention makes it possible to use an optical pickup in common with conventional optical disks. In a three-dimensional mark recording layer ( | 07-08-2010 |
20100208567 | Objective Lens and Optical Pickup Apparatus - An objective lens for an optical pickup apparatus is disclosed that can record and/or reproduce information compatibly for different optical discs with stability regardless of an environmental temperature change, in spite of its simple structure, and provides an optical pickup apparatus employing the objective lens. The objective lens includes: an optical surface which at least includes a central area, a peripheral area, and a most peripheral area. The objective lens is a single lens formed of plastic. The central area includes a first optical path difference providing structure. The peripheral area includes a second optical path difference providing structure. The objective lens further includes an optical path difference providing structure for correcting a temperature characteristic, where the optical path difference providing structure corrects an aberration caused by a temperature change of the objective lens. | 08-19-2010 |
20100208569 | OPTICAL PICKUP DEVICE - An optical pickup device has an astigmatism element, a polarization setting element, and a polarizer. The astigmatism element converges laser light reflected on a disc in a first direction and a second direction to form a first focal line and a second focal line. The polarization setting element makes polarization directions of light fluxes different from each other, the light fluxes being obtained by dividing a light flux of the laser light transmitted through the astigmatism element into two by a straight line parallel to the first direction. The polarizer transmits light having polarization directions obtained by inverting the polarization directions set by the polarization setting element with respect to the straight line parallel to the first direction, respectively. | 08-19-2010 |
20100214902 | OPTICAL PICKUP AND OPTICAL DISC DEVICE - An optical pickup includes: a light source outputting a light beam; an objective lens collecting the light beam on a target recording layer as a target of plural recording layers provided in an optical disc; a lens moving unit moving the objective lens in a tracking direction nearly orthogonal to track grooves helically or coaxially formed in the target recording layer; a collective lens collecting a reflected light beam formed when the light beam is reflected by the optical disc; a diffraction optical element diffracting part of the reflected first-order light beam in predetermined directions as first, second, third and fourth beams; and a photodetector receiving the first and second beams using first and second light receiving areas, and generating light reception signals, and receiving the third and fourth beams using third and fourth light receiving areas, and generates light reception signals. | 08-26-2010 |
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 |
20100226234 | Optical Head Device and Optical Information Recording/Reproducing Device - To provide an optical head device, which can detect an excellent focus error signal for a dual layer optical recording medium, and optical information recording/reproducing device. Reflected light from a dual layer optical recording medium is diffracted by a diffractive optical element divided into four regions, and is received by a photodetector. Optical spots are equivalent to negative first order diffracted light from the four regions of the diffractive optical element, and are received by four dual-divided light receiving sections, respectively, to be used for detection a focus error signal by a Foucault's method. The four dual-divided light receiving sections are provided with positive component light receiving sections for outputting the received light as a positive component of the focus error signal and negative component light receiving sections for outputting the received light as a negative component of the focus error signal, respectively. When a signal layer of the optical recording medium is far from an objective lens by a defocusing quantity equivalent to an interval between the first layer and the second layer from a just focus position, a diffraction direction of a diffracted light generated from the reflected light from the signal layer is set so as that the diffracted light spreads to the positive component light receiving section and the negative component light receiving section, and a plurality of the positive component light receiving sections and a plurality of negative component light receiving sections are arranged. | 09-09-2010 |
20100232281 | OPTICAL RECORDING HEAD AND OPTICAL RECORDING APPARATUS - An optical recording head includes: a light source; a slider comprising a wave guide which irradiates light from the light source to a recording medium, wherein a grating coupler is formed on an end portion at an opposite side of the waveguide relative to the light source; and an optical element which comprises a diffraction grating and introduces the light from the light source to the grating coupler through the diffraction grating. The optical element deflects the light from the light source so that the light is incident into the grating coupler with a deflection angle larger than 90 degrees with respect to a direction in which the light proceeds when the light is incident into the optical element. | 09-16-2010 |
20100232282 | OPTICAL PICKUP DEVICE - An optical pickup device radiates laser light to a disc having a plurality of recording layers in a direction of lamination. The optical pickup device includes an astigmatic element and a spectral element. The astigmatic element allows reflected light from the disc to converge in a first direction and form a first focal line at a first position, and allows reflected light to converge in a second direction and form a second focal line at a second position closer to the disc than the first position. The spectral element splits a reflected light flux in two along a straight line parallel to the first direction and turns traveling directions of the split two light fluxes into directions separated from each other. Here, the spectral element is interposed between the second focal line of the reflected light from a target recording layer and the second focal line of the reflected light from a deeper recording layer than the target recording layer. The photodetector is interposed between the first and second focal lines of the reflected light from the target recording layer. | 09-16-2010 |
20100265809 | OPTICAL PICKUP DEVICE - Provided is an optical pickup device capable of stabilizing a tracking signal and a focusing signal and of preventing quality deterioration of a data signal by eliminating a multi-layer crosstalk. Of reflected lights from a multi-layer disc, a reflected light from a target layer is split into two by a light flux splitting optical system so that the reflected light is spread out toward two directions with respect to a central line, and then the split lights are condensed. In this case, a reflected light from another layer does not reach a condensing position of the reflected light from the target layer, and only the reflected light from the target layer can be detected by a detector. Accordingly, a crosstalk from the another layer is eliminated. | 10-21-2010 |
20100271925 | OPTICAL HEAD, OPTICAL ELEMENT WITH DIFFRACTION GRATING, OPTICAL DISC DEVICE AND INFORMATION PROCESSING DEVICE - An optical head ( | 10-28-2010 |
20100284259 | Objective Lens, Optical Pickup Apparatus, and Optical Information Recording Reproducing Apparatus - An objective lens includes a first optical path difference providing structure in which a first basic structure and a second basic structure are overlapped together, and a second optical path difference providing structure in which a third basic structure, a fourth basic structure, and a fifth basic structure are overlapped together. The first and third basic structures emit diffracted light fluxes with the same diffraction order having the maximum light amount. The second and fourth basic structures emit diffracted light fluxes with the same diffraction order having the maximum light amount. The fifth basic structure emits 0th-order diffracted light fluxes with the maximum light amount, for the first light flux, emits 0th-order diffracted light fluxes with the maximum light amount, for the second light flux, and emits Gth-order diffracted light fluxes with the maximum light amount, for the third light flux, where G is an integer excluding zero. | 11-11-2010 |
20100309770 | Optical head device and optical information recording/reproducing device - To provide an optical head device and an optical information recording/reproducing device for recording/reproducing a signal on/from an optical recording medium having two recording layers without generating the disturbance on the track error signal detected with differential push-pull method even if the interval between the target layer and the non-target layer changes. The light beam emitted from a semiconductor laser is divided into a zeroth order main beam and a positive and a negative first order diffracted light sub-beams by a diffractive optical element. The light beams are applied onto a disk by an objective lens. The reflected light beam of the main beam and reflected light beams of the sub-beams from the disk are received by a photodetector. From the output of the photodetector, a differential push-pull signal is calculated, and used as a track error signal. The sub-beams become Laguerre-Gauss beams by the diffractive optical element. | 12-09-2010 |
20100322059 | OBJECTIVE LENS, OPTICAL PICKUP, AND OPTICAL DISC APPARATUS - Provided is an objective lens for selectively focusing each of light beams having three wavelengths λ | 12-23-2010 |
20100322060 | OBJECTIVE LENS, OPTICAL PICKUP AND OPTICAL DISC APPARATUS - Provided is an objective lens used in an optical pickup that performs recording and/or reproducing of information signals on three different types of optical discs using different wavelengths. The objective lens is configured to collect light beams with the at least three wavelengths λ | 12-23-2010 |
20110013502 | OPTICAL PICK-UP AND OPTICAL INFORMATION RECORDING AND REPRODUCING APPARATUS - An optical pick-up which permits the relative position of a diffracting optical element and a photodetector to be adjusted by feedback control with signals which are generated when more than one kind of diffracted light differing in order is received, the diffracted light occurring as the reflected light from the optical disc is divided and diffracted by the diffracting optical element having multiple regions. The photodetector which detects the light beam passing through the central region of the diffracting optical element and generates RF signals is juxtaposed with sub-photodetectors, so that they receive reflected stray light from out-of-focus layers and perform computation to calculate the reflected stray light component which the RF signal detector receives, thereby detecting only the component of signals of the reflected light from a target layer. | 01-20-2011 |
20110026389 | OPTICAL PICKUP DEVICE AND OPTICAL DISC DEVICE - An optical pickup device includes an astigmatism element which sets focal line positions to be defined by convergence of laser light away from each other, a diffraction element which diffracts four light fluxes obtained by a light flux of the laser light to disperse the four light fluxes from each other, and a photodetector having a first sensing section and a second sensing section which respectively receive m-th order diffraction light and n-th order diffraction light of the four light fluxes. In this arrangement, the first sensing section receives eight light fluxes obtained by dividing the four light fluxes of the m-th order diffraction light by two straight lines to output detection signals of the number less than eight. | 02-03-2011 |
20110032811 | DIFFRACTIVE OPTICAL ELEMENT, OBJECTIVE OPTICAL SYSTEM INCLUDING THE SAME, AND OPTICAL PICKUP INCLUDING THE SAME - A diffractive optical element includes a first optical part and a second optical part bonded to each other with a bonded surface therebetween configured as a diffraction surface. In this diffractive optical element, the diffraction order of diffracted light with the largest quantity of light out of diffracted light for one of a plurality of kinds of laser beams obtained on the diffraction surface is different from the diffraction order for at least another laser beam. | 02-10-2011 |
20110044152 | OPTICAL PICKUP AND OPTICAL DISC APPARATUS - An optical pickup includes a light source emitting a light beam, a diffraction element diffracting the light beam to separate it into a main beam and a sub beam, an objective lens focusing the main and sub beams onto a desired recording layer of an optical disc, a lens moving section moving the objective lens in focusing and tracking directions, a light-separating element separating a reflected light beam, formed by reflecting each of the main and sub beams at the recording layer, into multiple beam components and allowing the reflected light beam to travel without rotating an image thereof, and a light-receiving element having multiple light-receiving regions that optically receive the reflected light beam and generating a light reception signal based on the amount of received light to allow a signal processing section to generate a focus error signal and a tracking error signal based on the light reception signal. | 02-24-2011 |
20110063967 | OPTICAL PICKUP DEVICE AND OPTICAL DISC APPARATUS USING THE SAME - A diffractive optical element having a diffraction region for diffracting a part of a luminous flux is mounted and an unwanted luminous flux generated in a multi-layer optical disc is suppressed from entering a photodetector surface. Using the above-described structure, fluctuation of a tracking error signal can be suppressed from being caused by the unwanted luminous flux and preferable recording or reproduction quality can be obtained also in the multi-layer optical disc. | 03-17-2011 |
20110075541 | OPTICAL INFORMATION RECORDING/REPRODUCING OPTICAL SYSTEM AND OPTICAL INFORMATION RECORDING/REPRODUCING APPARATUS - An optical information recording/reproducing optical system where resin material has Tg>115° C., first, second and third films are on an optical disc side of an objective lens and surfaces of an optical element, respectively, a light source side of the objective lens has a fourth film having four or more layers not containing Ti, each of the first, second and third films includes a non-high refractive index layer made of one of silicon oxide, aluminum oxide, aluminum fluoride and magnesium fluoride or a mixture of at least two of them, each of the first, second and third films is not made of one of Ti, Ta, Hf, Zr, Nb, Mo and Cr, a layer of the fourth film closest to a base material is the non-high refractive index layer. The fourth film satisfies 350<λ | 03-31-2011 |
20110075542 | OPTICAL INFORMATION RECORDING/REPRODUCING OPTICAL SYSTEM AND OPTICAL INFORMATION RECORDING/REPRODUCING APPARATUS - An optical information recording/reproducing optical system, comprising a light source; an optical element converting a laser beam into a substantially collimated beam; and an objective lens, wherein a wavelength λ (unit: nm) of the laser beam falls within a range of 400<λ<410, the optical element and the objective lens are made of same resin materials or different resin materials having a glass transition temperature of Tg>115° C., each of optical surfaces is configured not to have an optical thin film which contains at least one of or elements of titanium, tantalum, hafnium, zirconium, niobium, molybdenum and chromium, each of optical surfaces of the optical element is provided with an antireflection film made of one of or a mixture of at least two of silicon oxide, aluminum oxide, aluminum fluoride and magnesium fluoride, and a following condition is satisfied. | 03-31-2011 |
20110103215 | Optical Pickup Apparatus - An optical pickup apparatus, which reads signals recorded on first and second signal recording layers of an optical disc, includes: a laser diode; an objective lens to condense a laser beam to the first and second signal recording layers; and a collimating lens disposed in a light path of the laser beam between the laser diode and the objective lens and configured to correct a spherical aberration by moving in a light axis direction of the laser beam, and the objective lens includes a bifocal lens and is configured such that a second focal point does not coincide in position with the second signal recording layer when a first focal point coincides in position with the first signal recording layer, and the first focal point does not coincide in position with the first signal recording layer when the second focal point coincides in position with the second signal recording layer. | 05-05-2011 |
20110110215 | Optical Pickup Apparatus - An optical pickup apparatus comprises: a first laser diode that generates a first laser beam having a first wavelength; a second laser diode that generates a second laser beam having a second wavelength longer than the wavelength; a third laser diode that generates a third laser beam having a third wavelength longer than the first wavelength and shorter than the second wavelength; an objective lens having an inner, outer, intermediate regions on an incident surface, the first laser beam being condensed on a signal recording layer of a first optical disc by condensing actions of the inner and outer regions, the second laser beam being condensed on a signal recording layer of a second optical disc by condensing actions of the inner and intermediate regions, the third laser beam being condensed on a signal recording layer of a third optical disc by condensing actions of the inner and intermediate regions. | 05-12-2011 |
20110122754 | Deflection Optical Element, Optical Recording Head and Optical Recording Apparatus - Disclosed is a deflection optical element, which makes it possible to deflect an incident light so as to couple the incident light to an optical element disposed in the later stage without deteriorating the optical efficiency. The deflection optical element, which deflects an incident light coming along a first optical axis at a deflection surface and emits an emission light propagating along a second optical axis so as to couple the emission light to either a diffraction grating or a refracting optical system, comprises at least one diffracting surface and at least one reflecting surface, wherein the angle θn, an angle θt derived as a total diffraction angle caused by the at least one diffracting surface, and an angle θa, which is formed at a second intersection of the first optical axis and the second optical axis, fulfill a conditional relationship of: | 05-26-2011 |
20110141873 | DIFFRACTION GRATING, ABERRATION CORRECTION ELEMENT AND OPTICAL HEAD DEVICE - There is provided a diffraction grating including a convex portion and a concave portion which are used for lights having different wavelengths λ | 06-16-2011 |
20110199882 | Objective Lens and Optical Pickup Device - There are provided an optical pickup apparatus which can record/reproduce information properly at a time of temperature change or of using a multilayer disc, and an objective lens for use in the same. When temperature changes, spherical aberration resulting from a change in refractive index of objective lens OBJ increases. Therefore, collimation lens CL is moved by uniaxial actuator AC | 08-18-2011 |
20110211437 | OPTICAL PICKUP DEVICE AND OPTICAL DISC APPARATUS - An optical pickup device including: a laser diode for emitting laser light; an objective lens which irradiates an optical beam emitted from the laser diode; an actuator which displaces the objective lens in a radius direction of the optical disc; a grating for branches an optical beam reflected by an information recording layer into plural regions; and one photodetector having plural light receiving parts for receiving the branched optical beams, wherein the photodetector has a first light receiving part which detects zero-th order grating diffracted light and plural second light receiving parts which detecting grating diffracted light having an order not less than that of ±first order grating diffracted light; a detected signal of the zero-th order grating diffracted light is defined as a reproduction signal; and a detected signal of the grating diffracted light is defined as a signal for servo controlling. | 09-01-2011 |
20110305131 | INFORMATION RECORDING MEDIUM, INFORMATION SUPPLY SYSTEM, AND OPTICAL INFORMATION DEVICE - An optical disk compliant with both a conventional optical disk such as a BD, HD DVD, and the like and a next-generation high-density optical disk according to a near-field light recording system and the like is provided. | 12-15-2011 |
20120002532 | Optical Pickup Device And Optical Disc Apparatus - An optical pickup device includes a semiconductor laser for emitting laser light, an objective lens for irradiating luminous flux emitted from the semiconductor laser to an optical disc, a branching element having a plurality of regions for branching luminous flux reflected from the optical disc to a plurality of fluxes, and a photodetector having a plurality of light receiving parts which receive luminous flux branched by said branching element. Luminous flux which enters at least two regions arrayed along a direction which is made substantially coincident with a tangential direction of the optical disc in regard to substantially a center of the branching element is arranged along a direction which is made substantially coincident with a radial direction of the optical disc on the photodetector. | 01-05-2012 |
20120069724 | OPTICAL PICKUP APPARATUS - An optical-pickup apparatus includes: a laser diode; an objective lens; a diffraction grating; a photodetector including main-beam-, first-sub-beam-, and second-sub-beam-light-receiving portions; a quarter-wave plate having either a second area allowing a reflected-laser beam to pass therethrough without polarization or a third area allowing the reflected beam to pass therethrough at a polarization angle different from that of the first area; and a polarizing member having a separate-light-amount ratio set therefor with respect to the reflected beams passing through the second or third area and an area excluding the second or third area from the first area, such that proportions of the reflected beams passing therethrough toward the photodetector are different, thereby decreasing an irradiation level when the first- and second-sub-beam-light-receiving portions are irradiated, as stray light, with the reflected beam reflected from either one, not subjected to a signal-reading operation, of the first- and second-signal-recording layers of an optical disc. | 03-22-2012 |
20120155240 | OPTICAL PICK-UP APPARATUS WITH DIFFRACTIVE OPTICAL ELEMENT AND OPTICAL RECORDING/REPRODUCING APPARATUS HAVING THE SAME - An optical pick-up apparatus for reproducing information recorded on an optical recording medium or recording information on the optical recording medium is provided. The optical pick-up apparatus includes a light source unit which generates beams; a diffraction element which diffracts the generated beams; and an objective lens which focuses a p order diffracted beam which is used for recording and reproducing information among a plurality of diffracted beams which are diffracted by the diffraction element on any one of a plurality of information layers which are formed on an optical recording medium. A p±1 order diffracted beam which is not used for recording and reproducing information is focused away from the plurality of information recording layers and on the surface of the optical recording medium. | 06-21-2012 |
20120218878 | Objective Lens, Optical Pickup Apparatus, and Optical Information Recording Reproducing Apparatus - An objective lens a first optical path difference providing structure in which a first basic structure and a second basic structure are overlapped with each other. The first basic structure is a blaze-type structure which emits a Xth-order diffracted light flux, when the first light flux passes through the first basic structure, where the value of X is an odd integer. At least a part of the first basic structure arranged around an optical axis includes a step facing an opposite direction to the optical axis. The second basic structure is a blaze-type structure which emits a Lth-order diffracted light flux, when the first light flux passes through the second basic structure, where the value of L is an even integer. At least a part of the second basic structure arranged around the optical axis includes a step racing the optical axis. | 08-30-2012 |
20120250487 | ELASTIC MEMBER, MOUNTING STRUCTURE OF OPTICAL ELEMENT, AND PICKUP APPARATUS HAVING THE SAME - A mounting structure of an optical element, includes: an optical element; an elastic member usable when the optical element is mounted; and a holding unit configured to be mounted with the optical element and the elastic member, the elastic member configured to be pressed into the holding unit, the holding unit configured to be mounted with the optical element by use of the elastic member. | 10-04-2012 |
20120257488 | METHOD AND APPARATUS FOR READING FROM A NEAR-FIELD OPTICAL RECORDING MEDIUM, AND NEAR-FIELD LENS FOR THE APPARATUS - A method and an apparatus for reading from a near-field optical recording medium are described. The apparatus includes:
| 10-11-2012 |
20120320727 | OPTICAL PICKUP AND OPTICAL READ/WRITE APPARATUS - An exemplary optical pickup comprises: a light source with first and second emission points; an optical branching element which branches light emitted from the first emission point into multiple light beams including a first main beam and first sub-beams and which also branches light emitted from the second emission point into multiple light beams including a second main beam and second sub-beams; an optical system which condenses the multiple light beams produced by the optical branching element onto an optical storage medium, thereby making the first and second main beams form a write light beam spot and a read light beam spot, respectively, on a target recording track on the storage medium and making the first and second sub-beams form reference light beam spots and other light beam spots somewhere on the storage medium other than the target recording track. | 12-20-2012 |
20130003515 | APPARATUS FOR READING FROM AND/OR WRITING TO A NEAR-FIELD OPTICAL RECORDING MEDIUM - An apparatus for reading from or writing to a near-field optical recording medium capable of detecting tilt and spherical aberration is described. The apparatus comprises a light source for generating a reading light beam, a near-field lens, an aberration compensation element, and a diffractive optical element. The diffractive optical element is switchable between a far-field mode and a near-field mode and is adapted to generate a main light beam and four or more sub-beams from the reading light beam for determining at least a cover layer thickness error signal. For this purpose it has an outer region with a first grating period and an inner region having a diameter smaller than an effective numerical aperture of the near-field lens, which in the near-field mode has a second grating period and which has a switchable inner area having a diameter smaller than a far-field numerical aperture of the near-field lens, which in the far-field mode has the first grating period. The aberration compensation element is adapted to be adjusted based on the thickness error signal when the diffractive optical element is in the near-field mode. | 01-03-2013 |
20130003516 | OPTICAL PICKUP DEVICE - An astigmatism element converges laser light in a first direction for generating a first focal line, and converges the laser light in a second direction perpendicular to the first direction for generating a second focal line. A light separating element guides the laser light entered into two first areas and into two second areas to four positions different from each other. The light separating element imparts a light separating function to the laser light entered into the first two areas in directions identical to each other and with magnitudes different from each other, and imparts a light separating function to the laser light entered into the two second areas in directions identical to each other and with magnitudes different from each other. | 01-03-2013 |
20130010583 | OPTICAL PICK UP, OPTICAL DRIVE DEVICE, AND LIGHT IRRADIATION METHOD - The present invention relates to an optical pick, an optical drive device, and a light irradiation method capable of suppressing a generated amount of shift Δx of a spot position. | 01-10-2013 |
20130088948 | OPTICAL READ/WRITE APPARATUS - An optical read/write apparatus as an embodiment of the present invention includes: a light-splitting element configured to split a light beam emitted from a light source into multiple light beams including a write beam and a read beam; an optical system configured to converge the write and read beams onto the same track on an optical storage medium; a photodetector including a light receiving element configured to detect the read beam reflected from the optical storage medium and output an electrical signal; and a divider configured to generate a read signal by dividing the signal detected by the light receiving element by a signal that represents a write modulated component and that is obtained by detecting a part of the light beam emitted from the light source. | 04-11-2013 |
20130107692 | OPTICAL PICKUP AND OPTICAL READ/WRITE APPARATUS | 05-02-2013 |
20130229902 | Objective Lens for Optical Pickup Device, Optical Pickup Device, and Optical Information Recording/Reproducing Device - An optical pickup apparatus including an objective lens capable of enhancing temperature characteristics and wavelength characteristics, and which enables compatibility for three types of optical discs of BDs, DVDs, and CDs by using the objective lens in common, an optical information recording and reproducing apparatus, and an objective lens suitable for it. In a first optical path difference providing structure in which at least a first basic structure and a second basic structure are superimposed on each other, an amount of a level difference in an optical axis direction can be reduced, whereby it becomes possible to suppress the lowering of a diffraction efficiency when wavelength changes. Further, in the first basic structure and the second basic structure deterioration of the spherical aberration due to the change of the refractive index of the objective lens can be corrected by utilizing a phenomenon that the wavelength of the light source rises similarly due to a rise in the environmental temperature. | 09-05-2013 |
20130279318 | DATA STORAGE AND RETRIEVAL - The invention provides for a recording method comprising the steps of modulating a first light beam; directing a second light beam to interfere with the first light beam to produce an interference pattern in a region of a recording medium; forming an optical device in the medium responsive to the interference pattern, wherein optical characteristics of the optical device are varied responsive to variations in the interference pattern. A method of playback, a recording and/or reading head and data carriers are also claimed. An example relates to a full diffraction analogy of gramophone recording. The interference of two beams, one of which is functionally linked to an audio signal, results in a change of the diffractive structure that instantly reflects the change of the input signal. On playback the diffracted light beam oscillates in the same way as the gramophone needle would vibrate. Another aspect of the disclosure relates to multilevel digital recording using holographic and/or diffractive structures. | 10-24-2013 |
20150380041 | OPTICAL DISC INFORMATION DEVICE AND INFORMATION PROCESSING DEVICE - An optical disc information device is an optical disc information device for reproducing and/or recording information with respect to an optical disc including a track in the form of a groove, and capable of recording information in a land portion and in a groove portion of the groove. The optical disc information device includes a laser light source, an objective lens, a transmittance limiting element, a dividing element, a light detector, a central amplifier, at least two end amplifiers, a gain controller, an adder, a reproduction signal processor, and a control signal processor. The transmittance limiting element includes a first central region, and at least two first end regions which interpose the first central region therebetween, and attenuates light passing through at least the first end regions out of a light flux emitted from the laser light source more strongly than light passing through the first central region. | 12-31-2015 |