Abstract: In an optical pickup device for emitting at least two laser beams suitable for respective optical recording mediums selectively operated on an optical disk driver so that a signal is read out from and/or recorded onto the selected one of the optical recording mediums, an anamorphic system is arranged to change a cross-sectional shape of one of the laser beams from an oval toward a circle between a divergence point and a confluence point along the one of the laser beam between an upstream common optical paths of the laser beams from the light beam source and a downstream common optical paths of the laser beams toward the objective lens, at which divergence point the laser beams from the upstream common optical path diverge from each other, and at which confluence point the laser beams converge into the downstream common optical path.

Abstract: An optical pickup device and an optical recording and reproducing apparatus are suitable for use with a near-field optical recording and reproducing system.

Abstract: An optical pick-up able to reduce a change of an optical axis of a light beam emitted to a photodetector when the optical element is tilted. An optical element in the optical pick-up is struck with an incident light beam from a first surface of a first prism, reflects the light beam refracted at the first surface at the second surface 161b, refracts the reflected light beam at the joined surfaces of the first prism and the second prism, and further refracts the refracted light beam at the first surface of the second prism to form an emitted light beam. The direction of the incident light beam and the direction of the emitted light beam perpendicularly intersect in the same plane.

Abstract: An optical pickup device as integrated into a disk device which drives optical disks is described. To provide a highly-reliable optical pickup device: without attenuation of the power of the laser beam used to form a laser spot on the optical disk, accurately monitoring the amount of light emission from the semiconductor laser element, and unaffected by the nonuniform reflectance and permeability of the reflection film and by variations in environmental conditions such as temperature and humidity.

Abstract: There is provided an optical pickup device comprising a laser light source for emitting a laser beam, an object lens for focusing the laser beam onto the recording surfaces of layers 0 and 1 of an optical disk and condensing the laser beam onto the recording surfaces, photodetectors for receiving the laser beam reflected by the optical disk, and a diffraction grating for diffracting a part of the reflected laser beam toward the photodetectors, wherein data can be simultaneously written to layers 0 and 1. The photodetector detects the reflected light from layer 0 after being refracted by the diffraction grating, and detects the reflected light from layer 1 without being refracted, so that the data of layers 0 and 1 can be simultaneously read. Thus, data can be simultaneously read from and written to the recording surfaces of a plurality of layers of an optical disk.

Abstract: An electromagnetically controlled drive system for accessing a data storage medium comprises an optical signal generator and a reflector element adapted to receive an optical signal from the optical signal generator. The reflector element is also adapted to direct the optical signal toward the data storage medium. The system also comprises an electromagnetic element adapted to generate an electromagnetic field proximate to the reflector element. The reflector element is adapted to respond to the electromagnetic field to move the optical signal relative to the data storage medium in response to a change in the electromagnetic field.

Abstract: A recording head for use in conjunction with a magnetic storage medium, comprises a waveguide for providing a path for transmitting radiant energy, a near-field coupling structure positioned in the waveguide and including a plurality of arms, each having a planar section and a bent section, wherein the planar sections are substantially parallel to a surface of the magnetic storage medium, and the bent sections extend toward the magnetic storage medium and are separated to form a gap adjacent to an air bearing surface, and applying a magnetic write field to sections of the magnetic recording medium heated by the radiant energy. A disc drive including the recording head and a method of recording data using the recording head are also provided.

Abstract: A light emitted from a light source (11) or a return light from a magneto-optical discs (7a, 7b, 7c or 7d) is transmitted by a polarization maintaining optical fibers (15a, 15b, 15c or 15d). Phase difference generators (16a, 16b, 16c and 16d) are disposed in optical paths, respectively, for these light beams to generate a phase difference which is used to cancel, or multiply by an integer multiple of &pgr;, a phase difference between field vibration components, raised in the light due to the birefringence of the polarization maintaining optical fiber (15a, 15b, 15c or 15d) when the light is propagated through the latter.

Abstract: An optical head with a plurality of semi-conductor laser chips for use in reducing inclination or gradient of more than one beam presently falling onto a focusing lens is disclosed. To this end, a double mirror or alternatively beam reshaping means is disposed which has different reflection planes for permitting reflection of a plurality of laser beams incoming from the semiconductor laser chips.

Abstract: An optical disc drive compatible with optical discs of different types, for example, is provided. For focusing, through an optical system used in common with the different types of optical discs, a laser beam emitted from a selected one of a plurality of light sources disposed apart from each other radially of the optical disc, the optical system is moved radially of the optical disc corresponding to the selection of the light source for emitting the laser light. Namely, it is possible to prevent the optical property from being deteriorated when a single optical pickup is used in common with such optical discs of different types.

Abstract: An optical pickup device has first and second light sources that emit first and second laser beams of different wavelengths, an object lens that concentrates the first and second laser beams on a data recording surface of an optical disk, an optical separator disposed between the first and second light sources and the object lens, and an optical monitor that detects a quantity of light of the second laser beam. The optical separator has a wavelength selecting film that, on one hand, reflects the first laser beam emitted from the first light source toward the object lens and, on the other hand, transmits the second laser beam emitted from the second light source to the object lens, and a reflector that reflects a part of the second laser beam emitted from the second light source toward the optical monitor.

Abstract: A optical device including conductive films having a first and second surfaces, one hole, surface specific shapes periodically, and a layer inserted as an intermediate layer between the first and the second surface of conductive films. The intermediate layer has the effect for improving surface roughness of the surface of conductive film. A light incident upon one surface enhances an intensity transmitted though the hole.

Abstract: The present invention provides an optical device that eliminates side lobes or their components from a super-resolution optical spot, and that is capable of electrically switching between super resolution and normal resolution as needed in simple manner. The optical device having a light generating unit for generating incident light and a lens system for collecting the incident light and producing a super-resolution optical spot containing a main lobe and a side lobe by modulating a portion of the incident light, comprises a polarization vector modulation unit for making polarization vectors of the side lobe and the main lobe differ from each other so that one or the other of the polarization vectors can be selected, and a polarization selective unit for eliminating the side lobe by selecting the polarization vector of the main lobe.

Abstract: An optical pickup device includes an illuminating optical system for focusing light beams, split in a main beam and at least one side beam, onto a track on an information storage surface of an optical storage medium to form optical spots thereon. The device also includes a light detecting optical system for introducing return light reflected back from the information storage surface and a polarizing optical element. The polarizing optical element has regions split at the center of an optical path by a parting line extending at least either in a direction of extension of the track or in a direction perpendicular to the direction of extension. The polarizing optical element also splits the main beam return light at least in two for each of the regions on a plane perpendicular to the optical path of the return light of the reflected main beam in the light detecting optical system. The polarizing optical element is disposed where the return light of the main and side beams is spatially separated.

Abstract: An optical pickup records information on a recordable and reproducible disk and reads information therefrom. The optical pickup includes a laser light source for emitting first laser light in case of a reproduction mode for reproducing information from the disk and emitting second laser light in case of a recording mode for recording information on the disk. A collimating lens collimates the laser light emitted from the laser light source. A chromatic aberration corrector includes prisms of respectively different material properties, for beam-shaping and dispersing the laser light collimated by the collimating lens so that chromatic aberration of an optical spot formed on the disk is corrected in which the chromatic aberration is generated by a difference between the wavelengths of the first and second laser lights. The beam-shaped and dispersed first and second laser lights are focused on the disk by an objective lens.

Abstract: A light source unit, which is employed in an optical head for an optical disc drive, is provided with a laser diode having a plurality of light emitting points. The plurality of light emitting points are spaced from each other by a predetermined minute amount. One of a plurality of laser beams having different wavelengths is selectively emitted from the plurality of light emitting points. The light source unit further includes a collimating lens that collimates each of the plurality of laser beams respectively emitted from the plurality of light emitting points. The plurality of laser beams passed through the collimating lens proceeds in different directions. The light source unit further-includes a transparent optical path compensation element having a predetermined dispersion characteristic. Each of the plurality of laser beams emerging from the collimating lens is emerged from the transparent optical path compensation element along the same optical path.

Abstract: A magneto-optical pickup includes a light source for emitting a light beam, the light beam traveling to an information recording medium along a first optical path, a first light receiving element group for detecting an error signal, a second light receiving element group for detecting a magneto-optical signal, the first and second light receiving element groups being situated substantially on one plane, a diffraction grating for diffracting light returned along the first optical path from the information storage medium, the diffracted light being directed toward the first light receiving element group, a polarization beam splitter for separating a part of the return light from the information storage medium, a beam of the separated part of return light traveling to the second light receiving element group along a second optical path, a mirror for bending the second optical path, the light beam reflected thereby being directed toward the second light receiving element group, and an anisotropic optical crystal

Abstract: An optical system and method for selective transmission of light between a source of light and set of storage disks along an optical path includes at least one polarization maintaining optical fiber optical fiber. Various noise reduction techniques are provided by substantially decreasing or eliminating spurious reflections (or the effects thereof) at end faces and of an optical fiber. In particular, various techniques, such as index matching, a cover slip method, or laser modulation, may be used to eliminate spurious reflections (or the effects thereof) at the front end face of the optical fiber. Various techniques, such index matching or multi-mode fiber splicing, may be used to eliminate spurious reflections (or the effects thereof) at the end face of the optical fiber.

Abstract: A device for reading from and/or writing to optical recording media, the device comprising a light source for producing a scanning beam, a photodetector for detecting the scanning beam reflected by the recording medium and a semi-transparent mirror arranged in the beam path for directing the scanning beam onto the recording medium and the reflected scanning beam onto the photodetector. An object of the invention is to improve a device of this type, in particular with regard to reducing the production costs. This object is achieved by the semi-transparent mirror being a plane-parallel plate with a layered structure, and a partially reflective layer being arranged between two small carrier plates.

Abstract: An optical pickup device with the capability to read data from and write data to different kinds of optical discs in different formats and a composite optical device used in the optical pickup device. An optical pickup device is made by combining two laser couplers LC1 and LC2 that are designed for optimum read/write specifications for optical discs which are different in format from each other. In one embodiment, two laser couplers LC1 and LC2 are incorporated on a common photodiode IC to form a single laser coupler, and the laser coupler is used in an optical pickup device.

Abstract: In order to condense the light beam on the second optical disc 1b, the opening limiting portion 20 for limiting the beam diameter is disposed between the condenser lens 14 for condensing the light beam on the first optical disc 1a and the light sources 2 and 8, so that the light beam is condensed most suitably with the condenser lens 14 when the first optical disc 1a is read. On the other hand, when the second optical disc is read, by the opening limiting portion 20 which limits the beam diameter, even if it is the light beam which corresponds to the second optical disc 1b, it is condensed most suitably with the condenser lens 14. Further, by changing the beam diffusion angle, the generation of the wave front aberration is restrained.

Abstract: The present invention provides for a optical head device having a beam-guiding optical device to bring beams of different wavelengths which are emitted by separate light sources together onto the same optical axis or to guide the beams onto a common photo receiving device. The beam-guiding optical device includes an incident plane and an exit plane and the incident plane and the exit plane are back to back. One of the incident plane and the exit plane has a stair-like surface wherein a step height between neighboring treads in the stair-like surface is set to cause a phase difference of n wavelength to one of the beams passing through the neighboring treads and n is equal to 1, 2, 3 . . . .

Abstract: In an optical pickup device for emitting at least two laser beams suitable for respective optical recording mediums selectively operated on an optical disk driver so that a signal is read out from and/or recorded onto the selected one of the optical recording mediums, an anamorphic system is arranged to change a cross-sectional shape of one of the laser beams from an oval toward a circle between a divergence point and a confluence point along the one of the laser beam between an upstream common optical paths of the laser beams from the light beam source and a downstream common optical paths of the laser beams toward the objective lens, at which divergence point the laser beams from the upstream common optical path diverge from each other, and at which confluence point the laser beams converge into the downstream common optical path.

Abstract: An optical information detecting apparatus includes a first optical system focusing an optical beam on a recording surface of a recording medium and a second optical system directing a reflection optical beam produced as a result of reflection of the optical beam by a recording surface of the recording medium to a photodetection unit. The second optical system includes a beam dividing element disposed so as to interrcept the reflection optical beam and divide the reflection beam into a plurality of optical beam elements traveling generally parallel with each other in the reflection optical beam, such that the plurality of optical beam elements reach the photodetection unit along respective optical paths.

Abstract: In an optical pickup used in a DVD player, a photo detector has a predetermined photo sensing area pattern for detecting a returning laser beam from an optical disc. The returning laser beam is originated from a first laser beam or a second laser beam. The first and the second laser beams are alternatively emitted from a two wavelength laser having first and second right sources. Either the first laser beam or the second laser beam travels to the optical disc through a grating, a polarizing beam splitter, a collimating lens, a rising mirror, and an object lens and is reflected by the optical disc. The reflected laser beam reflected from the optical disc travels to the photo detector as the returning laser beam through the object lens, the rising lens, the collimating lens, and the polarizing lens. The predetermined photo sensing area pattern enables the photo detector to detect the returning laser beam regardless of the origin of the returning laser beam.

Abstract: Disclosed is an optical disc apparatus compatible with both ROM type and RAM type optical discs having high density and large capacity. An optical disc apparatus includes: a disc control device including an optical disc (a magneto-optical disc), a spindle motor for rotating the optical disc, an objective lens for forming a light spot on the optical disc, and a control drive device which controls and drives the objective lens in the tracking direction of the optical disc, a semiconductor laser serving as a light source, a signal light transfer having a polarization-preserving optical fiber for guiding output light from the semiconductor laser to the objective lens, ¼ wave plates provided in optical paths on both sides of the polarization-preserving optical fiber, and signal detecting devices (polarization beam splitter and photo detectors) for detecting a servo signal, etc. from the reflected light from the optical disc.

Abstract: The optical pickup apparatus 100 uses a semiconductor laser element 50 integrated a first light emission source 36 for emitting a first laser beam with a second light emission source 40 for emitting a second laser beam, of which wavelength is different from that of the first laser beam. The optical pickup apparatus 100 is constructed so that a first half mirror functional surface 52b and a second half mirror functional surface 52c are provided in a beam splitter 52 to match an optical path in which the first laser beam passes through the first half mirror functional surface 52b of the beam splitter 52 and then is reflected at the second half mirror functional surface 52c and again is emitted from the first half mirror functional surface 52b to be directed toward a bifocal lens 54 with an optical path in which the second laser beam is reflected at the first half mirror functional surface 52b to be directed toward the bifocal lens 54.

Abstract: A beam is emitted from a radiation source such as a semiconductor laser and is converted to parallel light by a collimator lens. The light enters a surface A of a prism at an incidence angle &phgr; (an angle between the normal line of the surface A and the incident light), thus obtaining light refracted at a refraction angle &psgr; (an angle between the normal line and the refracted light). This refracted light is incident on the surface B of the prism to be reflected totally from this surface, and the reflected light is incident on the surface C of the prism. Then, the reflected light enters the surface B of the prism again and is transmitted through this surface. The transmitted light is converted to convergent light by an objective lens. The convergent light is transmitted through a surface of an optical disk substrate, thus being focused on a signal surface. An optical disk device that is thin beyond the physical limitations without changing the working distance and the numerical aperture can be obtained.

Abstract: An optical pickup head which utilizes two or three laser beams of different wavelengths for reading or writing data on different kinds of optical recording media through a same optical output path is disclosed. According to the present invention, a beam shaper located in optical paths of multiple laser beams is used. The beam shaper is composed of two prisms in which several laser beam interfaces are formed. Each laser beam interface is furnished with a specific coating for reflecting laser beam of a specific wavelength and transmitting and refracting laser beams of other wavelengths. Therefore, laser beams in different wavelengths can be shaped into a same optical output path for reading and writing data from optical recording media. The laser beams passing through the beam shaper can be eliminated of their chromatic aberrations, and improved their cross-sectional shapes to get higher usage efficiencies of the laser beams. And, the optical pickup head is constructed as a compact unit with small size.

Abstract: An optical pickup apparatus is provided with: a light source (20) for emitting a light beam; an optical system (21, 22, 24, 25, 26, 27), which comprises an optical element (24) having an incident surface (24a), to which an AR (Anti-Reflection) coat is not applied and to which the light beam emitted from the light source is inputted obliquely by a predetermined incident angle, for guiding one portion of the emitted light beam transmitted through the incident surface onto an information record medium (32) and guiding a reflection light of one portion of the emitted light beam reflected from the information record medium, and also reflecting another portion of the emitted light beam by the incident surface; a main light detector (30) for receiving the reflection light from the information record medium guided by the optical system and outputting a main detection signal corresponding to record information recorded on the information record medium; a monitor detector (23) for receiving another portion of the emitt

Abstract: A light source is provided for emitting a first beam having a far-field pattern of an elliptic shape. The first beam is a linearly polarized light having a first polarizing direction in a major axis of the elliptic shape. A half-wave plate is provided for rotating the polarizing direction of the first beam 90 degrees, thereby changing the first beam to a second beam. A beam splitter is provided for changing the elliptic shape of the second beam into a circular shape. The beam splitter is arranged to transmit the second beam and to reflect a third beam having a polarizing direction different from that of the second beam by 90 degrees. A quarter-wave plate is provided for transmitting the second beam from the beam splitter to apply it to an optical disc, and for changing the second beam reflected from the optical disc into the third beam. The third beam reflected from the beam splitter is applied to a photodetector.

Abstract: An optical information detecting apparatus includes a first optical system focusing an optical beam on a recording surface of a recording medium and a second optical system directing a reflection optical beam produced as a result of reflection of the optical beam by a recording surface of the recording medium to a photodetection unit, wherein the second optical system including a beam dividing element disposed so as to intercept the reflection optical beam and divide the reflection beam into a plurality of optical beam elements traveling generally parallel with each other in the reflection optical beam, such that the plurality of optical beam elements reach the photodetection unit along respective optical paths.

Abstract: The present invention relates to a device for reading from and/or writing to optical recording media (6), which has a light source (1) for producing a scanning beam (2), a photodetector (7) for detecting the scanning beam (2) reflected by the recording medium (6) and a semi-transparent mirror (3) arranged in the beam path for directing the scanning beam (2) onto the recording medium (6) and the reflected scanning beam (2) onto the photodetector (7).