Patent application number | Description | Published |
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 |
20080224028 | Optical head apparatus and optical information recording or reproducing apparatus - Light emitted from a light source and having a wavelength of 400 nm is reflected by a beam splitter (BS), and converged on a disk according to a next-generation standard. Reflection light therefrom passes through the BS and is received by a photodetector. Light emitted from a light source and having a wavelength of 660 nm is reflected by the BS and passes through the BS, and converged on a disk according to a DVD standard. Reflection light therefrom passes through the BS and is received by the photodetector. About 50% of light emitted from a light source and having a wavelength of 780 nm is reflected by the BS. The light passes through the BS and is then converged on a disk according to a CD standard. Reflection light therefrom passes through the BS. About 50% of the light passes through the BS and is received by the photodetector. Thus, recording and reproduction can be performed on any of disks according to a next-generation standard, DVD standard, and CD standard. With respect to disks according to the next-generation standard, a high optical output is obtained during recording and a high S/N ratio is obtained during reproduction. With respect to disks according to the CD standard, the amount of light received by the photodetector does not substantially vary even when birefringence of a disk varies. | 09-18-2008 |
20080273445 | OPTICAL HEAD DEVICE AND OPTICAL RECORDING AND REPRODUCING APPARATUS - An optical head device and an optical recording and reproducing apparatus using this optical head device, which can record information and reproduce the recorded information at any of optical recording media, such as a next generation optical recording medium, in which the wavelength of the light source is made to be shorter, the numerical aperture of the objective lens is made to be higher, and the thickness of the recording medium is made to be thinner, and conventional recording media of DVD and CD standards, are provided. A light having wavelength of 405 nm, emitted from one of optics, is inputted to an objective lens as a collimated light, and is focused on a disk having thickness of 0.1 mm. A light having wavelength of 650 nm, emitted from the other of optics, is inputted to the objective lens as a diverged light, and is focused on a disk having thickness of 0.6 mm. A spherical aberration, which remains for the light having wavelength of 650 nm, is decreased by the change of the magnification of the objective lens, further the decreased spherical aberration is decreased by using a wavelength selective filter. | 11-06-2008 |
20090016198 | OPTICAL HEAD DEVICE AND OPTICAL RECORDING AND REPRODUCING APPARATUS - An optical head device and an optical recording and reproducing apparatus using this optical head device, which can record information and reproduce the recorded information at any of optical recording media, such as a next generation optical recording medium, in which the wavelength of the light source is made to be shorter, the numerical aperture of the objective lens is made to be higher, and the thickness of the recording medium is made to be thinner, and conventional recording media of DVD and CD standards, are provided. A light having wavelength of 405 nm, emitted from one of optics, is inputted to an objective lens as a collimated light, and is focused on a disk having thickness of 0.1 mm. A light having wavelength of 650 nm, emitted from the other of optics, is inputted to the objective lens as a diverged light, and is focused on a disk having thickness of 0.6 mm. A spherical aberration, which remains for the light having wavelength of 650 nm, is decreased by the change of the magnification of the objective lens, further the decreased spherical aberration is decreased by using a wavelength selective filter. | 01-15-2009 |
20090046548 | OPTICAL HEAD APPARATUS AND OPTICAL INFORMATION RECORDING/REPRODUCING APPARATUS - An optical head apparatus of an optical information recording/reproducing apparatus is provided with a light source. An objective lens focuses an output light emitted by said light source on a disc optical recording medium for which a groove or a pit for tracking is provided. T photo-detector receives a reflected light reflected by said optical recording medium. A polarizing splitter unit splits said output light and said reflected light. A quarter-wave plate disposed between said polarizing splitter section and said objective lens. A birefringence compensating unit reduces a change in an amplitude of a track error signal caused by birefringence in a protective layer of said optical recording medium. | 02-19-2009 |
20090046554 | OPTICAL HEAD DEVICE AND OPTICAL INFORMATION RECORDING OR REPRODUCING APPARATUS EQUIPPED WITH SAME - [Problems] To provide an optical head device capable of obtaining a desirable track error signal and a lens position signal for both two types of optical media having different groove pitches. | 02-19-2009 |
20090052301 | Optical system for detecting data signal and tracking error signal including polarizing optical element - In an optical system, reflected light from the disk is diffracted by a hologram optical element, and received by an optical detector. A focusing error signal is detected from −1st-order diffracted light of the hologram optical element. A tracking error signal by the differential phase method, a tracking error signal by a push-pull method and the data signal recorded on the disk are detected from +1st-order diffracted light of the hologram optical element. A diffraction efficiency of the +1st-order diffracted light is higher than a diffraction efficiency of the −1st-order diffracted light. | 02-26-2009 |
20090121117 | Optical Head Device, Optical Information Recording/Reproducing Apparatus and Operation Method of Optical Information Recording/Reproducing Apparatus - An optical head device is provided with an objective lens ( | 05-14-2009 |
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 |
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 |
20090252011 | OPTICAL INFORMATION RECORDING/ REPRODUCING DEVICE AND OPTICAL INFORMATION RECORDING/ REPRODUCING METHOD - An optical information recording/reproducing device includes a liquid optical element containing a liquid crystal polymer layer in an optical head. A liquid crystal optical element drive unit drives a liquid crystal optical element having a first pattern electrode divided into a plurality of region at one side of the liquid crystal polymer layer in the optical axis direction. The first pattern electrode includes a first region arranged to surround the optical axis and second to ninth regions arranged outside the first regions in such a manner that the circumference is divided eight portions. The liquid crystal optical element drive unit applies a first effective voltage to the first region, a second effective voltage to the second and the sixth region, a third effective voltage to the third and the seventh region, a fourth effective voltage to the fourth and the eighth region, and a fifth effective voltage to the fifth and the ninth region. An average value of the second and the fourth effective voltage and an average value of the third and the fifth effective voltage are identical to the first effective voltage. The voltage applied to the respective regions of the pattern region of the liquid crystal optical element is decided in a short time so as to optimize the quality of the reproduction signal. | 10-08-2009 |
20090257339 | OPTICAL HEAD DEVICE AND OPTICAL INFORMATION RECORDING OR REPRODUCING APPARATUS - There is disclosed an optical head apparatus and an optical information recording or reproducing apparatus capable of obtaining a high light output at a recording time, and a high S/N at a reproducing time with respect to any of disks of next-generation, DVD, and CD standards. Light having a wavelength of 400 nm emitted from a semiconductor laser is almost all reflected by a beam splitter, and condensed on a disk of the next-generation standard. Light having a wavelength of 660 nm emitted from a semiconductor laser is almost all reflected by a beam splitter, almost all transmitted through the beam splitter, and condensed on the disk of the DVD standard. Light having a wavelength of 780 nm emitted from a semiconductor laser is almost all reflected by a beam splitter, almost all transmitted through the beam splitters and condensed on the disk of the CD standard. Reflected light from the disk is almost all transmitted through the beam splitters and received by a photodetector. | 10-15-2009 |
20090274020 | OPTICAL HEAD UNIT AND OPTICAL INFORMATION RECORDING/REPRODUCING APPARATUS - An optical head unit is configured as an optical head unit corresponding to an optical recording medium of BD standard, and an optical recording medium of HD DVD standard. A magnification-variable lens includes convex lens, concave lens, and convex lens. The magnification-variable lens allows each lens to be movable along the optical axis direction, and has the function of changing the ratio of diameter of light incident from the convex lens to the diameter of light that exits from the convex lens within a specific ratio. The magnification-variable lens emits light having a diameter corresponding to the numerical aperture, 0.85, of the objective lens towards the objective lens upon recording/reproducing on a disk of BD standard, and emits light having a diameter corresponding to the numerical aperture, 0.65, of the objective lens upon recording/reproducing on a disk of HD DVD standard. | 11-05-2009 |
20090290473 | OPTICAL HEAD DEVICE AND OPTICAL INFORMATION RECORDING OR REPRODUCING APPARATUS WITH THE SAME - [Problems] An optical head device and an optical information recording or reproducing apparatus are provided to detect an excellent track error signal for two-layer optical recording medium. | 11-26-2009 |
20100019126 | OPTICAL HEAD DEVICE, OPTICAL INFORMATION RECORDING/REPRODUCING DEVICE, AND OPTICAL INFORMATION RECORDING/REPRODUCING METHOD THEREOF - Between a semiconductor laser and a polarization beam splitter, a polarization direction control element, including a liquid crystal polymer layer divide into a plurality of concentric circle regions having different optical axis directions, is provided. A voltage is applied to the liquid crystal polymer layer at the time of recording. Since the polarization direction control element acts as a full wavelength plate for incident light, the light exiting the polarization beam splitter has an intensity distribution identical to that of the incident light and the rim strength in objective lens lowers. No voltage is applied to the liquid crystal polymer layer at the time of reproduction. Since the polarization direction control element operates as a half wavelength plate for rotating the polarization direction of the incident light more toward the central portion, the light exiting the polarization beam splitter has an intensity becoming lower toward the central portion as compared with the incident light, and the rim strength in an objective lens increases. | 01-28-2010 |
20100027384 | OPTICAL HEAD DEVICE, OPTICAL INFORMATION RECORDING/REPRODUCING DEVICE AND ERROR SIGNAL GENERATION METHOD - A diffractive optical element generates main and two sub beams from an output light of a light source. An objective lens focuses the main and two sub beams on an optical recording medium. An optical detector receives the main and two sub beams reflected by the optical recording medium. The diffractive optical element is divided into six regions having different optical characteristics by a tangential direction division line corresponding to the tangential direction of the optical recording medium, first and second radial direction division lines corresponding to the radial direction thereof. A light in the first sub beam passing an intersection of the first radial and tangential direction division lines passes a region near the center of the objective lens. A light in the second sub beam passing an intersection of the second radial and the tangential direction division lines passes a region near the center of the objective lens. | 02-04-2010 |
20100046353 | OPTICAL RECORDING MEDIUM, OPTICAL HEAD DEVICE AND OPTICAL INFORMATION RECORDING/REPRODUCING DEVICE - Light output from a laser is split into a first beam which is reflected light and a second beam which is transmitted light, by a polarization beam splitter. The polarization directions of the first beam and the second beam are orthogonal to each other. A disk includes a recording layer, a quarter wavelength plate layer, and a reflective layer. When information is recorded on the disk, the first beam, which travels inside the recording layer to the side of the reflective layer, and the second beam, which passes through the recording layer and is reflected at the reflective layer and travels inside the recording layer to the side opposite to the reflective layer, are focused on the same position. When information is reproduced from the disk, the second beam is blocked by a shutter, and the first beam reflected at the recording layer is received by a photodetector. | 02-25-2010 |
20100061216 | OPTICAL HEAD UNIT AND OPTCAL INFORMATION RECORDING/REPRODUCING APPARATUS - An optical head unit includes, apart from an objective lens toward a light source, an optical device that changes the image height of light incident onto the objective lens, wherein the optical device includes a concave lens and a convex lens. The objective lens is designed so that a coma aberration having a specific polarity occurs if the optical axis of the incident light tilts toward a specific direction. If the disk tilts, the convex lens is moved within the plane perpendicular to the optical axis, to change the image height of the light incident onto the objective lens, to thereby tilt the optical axis of light exiting from the convex lens with respect to the optical axis of light incident onto the concave lens. The objective lens generates a coma aberration having a polarity opposite to the polarity of the coma aberration attributable to the tilt of disk, to thereby cancel the coma aberration attributable to the tilt. | 03-11-2010 |
20100074077 | OPTICAL HEAD DEVICE AND OPTICAL INFORMATION RECORDING/REPRODUCING DEVICE - Provided are an optical head device and an optical information recording/reproducing device, which can record/reproduce information to/from at least three kinds of optical recording media of different standards. A light beam emitted from a semiconductor laser is converged on a disk by an objective lens, and a reflected light beam from the disk is received by a photodetector. The optical system includes a liquid crystal refracting lens which can change the focal distance continuously within a predetermined range. The liquid crystal refracting lens has an electrode, and corrects, when the voltage applied to the electrode is changed, such a spherical aberration in the emitting light as changes with the kind of the disk. Moreover, a liquid crystal aperture control element has an electrode, and changes the effective numerical aperture of the objective lens in accordance with the kind of the disk, when the voltage applied to the electrode is changed. | 03-25-2010 |
20100085495 | OPTICAL HEAD DEVICE AND OPTICAL INFORMATION RECORDING/REPRODUCING DEVICE - In front of the objective lens of an optical head deice, a birefringence correction element ( | 04-08-2010 |
20100085860 | OPTICAL HEAD DEVICE, AND OPTICAL INFORMATION RECORDING/REPRODUCING DEVICE AND OPTICAL INFORMATION RECORDING/REPRODUCING METHOD USING THE SAME - Light outputted from a semiconductor laser ( | 04-08-2010 |
20100142355 | OPTICAL HEAD DEVICE AND OPTICAL INFORMATION RECORDING OR REPRODUCING DEVICE - [Problems] To provide an optical head and an optical information recorder/reproducer in which a high signal/noise ratio can be attained for an RF signal. | 06-10-2010 |
20100220577 | OPTICAL HEAD DEVICE, OPTICAL INFORMATION RECORDING/REPRODUCING DEVICE, AND OPTICAL INFORMATION RECORDING/REPRODUCING METHOD - Polarization direction switching elements do not change the polarization direction of incoming light, in the case where a disc is an optical recording medium conforming to the HD DVD standards. At this time, light outputted from a semiconducted laser is collected on the disc by an objective lens, and reflection light from the disc is received by a light detector. In the case where the disc is an optical recording medium conforming to the BD standards, the polarization direction switching elements change the polarization directed of the incoming light by ninety degrees. At this time, light outputted from the semiconductor laser is collected on the disc by the objective lens, and reflection light from the disc is received by the light detector. Liquid crystal lenses correct spherical aberrations on an outgoing path and a returning path. | 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 |
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 |
20110026390 | OPTICAL INFORMATION RECORDING/REPRODUCING DEVICE, OPTICAL UNIT, AND OPTICAL INFORMATION RECORDING METHOD - An optical unit is provided with a light source; a light dividing means for dividing light emerging from the light source into a first light and a second light; a light converging means for converging the first and second lights at the same position in the recording layer in the manner that they face each other; a polarization state switching means for switching the polarization states of the first and second lights at the convergence point in the recording layer; and a light irradiation state switching means for switching between the state in which the optical cording medium is irradiated with both the first light and the second light and the state in which the optical recording medium is irradiated with only one of the first and second lights. | 02-03-2011 |
20110110207 | OPTICAL UNIT, CONTROL METHOD, AND OPTICAL INFORMATION RECORDING/REPRODUCING DEVICE - An optical unit includes an optical system for shining a laser beam on an optical recording medium having a recording layer and a focus control reference surface. The optical system is composed of an objective lens for focusing a recording/reproducing beam emitting from a first light source in the recording layer and focusing a focus control beam emitted from a second light source on the focus control reference surface, a first lens system disposed along an optical path of the recording/reproducing beam and capable of discretely varying a focus position of the recording/reproducing beam in a direction of a thickness of the recording layer, and a second lens system disposed along an optical path common to the recording/reproducing beam and the focus control beam and capable of continuously varying focus positions of the recording/reproducing beam and the focus control beam in a direction of a thickness of the recording layer. | 05-12-2011 |
20120075977 | OPTICAL INFORMATION RECORDING/ REPRODUCING APPARATUS AND OPTICAL INFORMATION RECORDING AND REPRODUCING METHOD - An optical information recording/reproducing device includes a liquid optical element containing a liquid crystal polymer layer in an optical head. A liquid crystal optical element drive unit drives a liquid crystal optical element having a first pattern electrode divided into a plurality of region at one side of the liquid crystal polymer layer in the optical axis direction. The first pattern electrode includes a first region arranged to surround the optical axis and second to ninth regions arranged outside the first regions in such a manner that the circumference is divided eight portions. The liquid crystal optical element drive unit applies an effective voltage to each region. The voltage applied to the respective regions of the pattern region of the liquid crystal optical element is decided in a short time so as to optimize the quality of the reproduction signal. | 03-29-2012 |
20130016139 | LIGHT SOURCE UNIT AND IMAGE DISPLAY DEVICEAANM Tomiyama; MizuhoAACI TokyoAACO JPAAGP Tomiyama; Mizuho Tokyo JPAANM Katayama; RyuichiAACI TokyoAACO JPAAGP Katayama; Ryuichi Tokyo JP - Provided is a light source unit that can solve a problem, namely, the inability to emit polarized light having high directivity. Active layer | 01-17-2013 |
20130021773 | WAVELENGTH PLATE, LIGHT EMITTING ELEMENT, AND IMAGE DISPLAY DEVICE USING THE LIGHT EMITTING ELEMENT - Provided is a wavelength plate that can increase incident angle tolerance. The wavelength plate in which a high refractive index layer and a low refractive index layer are alternately stacked, each layer having a concave-convex structure the period of which is equal to or shorter that a wavelength in one direction within a plane, includes, as periods in the thickness direction of the high refractive index layer and the low refractive index layer: a first period defined so that a used wavelength can belong to the first band of a photonic band structure; and a second period defined so that the used wavelength can belong to a wavelength side longer than the center wavelength of the second band of the photonic band structure. | 01-24-2013 |
20130021774 | LIGHT EMITTING ELEMENT AND IMAGE DISPLAY APPARATUS USING THE LIGHT EMITTING ELEMENT - The invention realizes a light emitting element having high efficiency, capable of increasing the luminance and capable of emitting linearly polarized light in which the light distribution characteristic has good symmetry. The light emitting element of the present invention has an active layer that produces light, and includes a polarizer layer having a first region that allows a polarization component in a first direction in the light produced in the active layer to pass therethrough and reflects other polarization components, and a second region that allows a polarization component in a second direction perpendicular to the first direction to pass therethrough and reflects other polarization components, a wavelength plate layer having a third region and a fifth region that the light exiting from the first region enters, and a fourth region and a sixth region that the light exiting from the second region enters, the wavelength plate layer causing the lights that have entered the third to sixth regions to exit as lights in the same polarized state, and a reflective layer that reflects the lights reflected by the first region and the second region. The directions of optical axes of the third region and the fifth region or the fourth region and the sixth region are perpendicular to each other. | 01-24-2013 |