Abstract: In an optical head device including a light source for emitting a light of a predetermined wavelength; a collimator lens for converting a divergence degree of the light; a folding mirror for folding a direction of the light emitted from the light source; an objective lens for converging the light on a recording surface of an optical disc; a photodetector for receiving the light reflected at the recording surface of the optical disc, and converting to an electric signal; and an optical path adjustment unit for guiding the light emitted from the light source to the collimator lens and guiding the light reflected at the recording surface of the optical disc to the photodetector; a wavelength plate for polarizing the light reflected by the folding mirror is arranged on an actuator base between the folding mirror and the objective lens.

Abstract: An optical pickup device which can more improve heat radiation efficiency and an optical disk apparatus including the optical pickup device are provided. The optical pickup device having a base (110), a laser unit (141), an optical system (140) which propagates a laser beam, and an adjusting member (142) includes a heat radiation part (146) which is fixed to a heat radiation surface (141b) of the laser unit and which conducts heat from the heat radiation surface to the adjusting member. Therefore, heat generated by the laser unit is transmitted to the adjusting member and then the base through the heat radiation part to make it possible to efficiently perform heat removal for the laser unit.

Abstract: The type of a disc is determined by detecting focus error signals and the amount of returned light while emitting light with a wavelength such as infrared light which maximizes the focal length and moving an objective lens in the direction of an optical axis. If the S shape and AS immediately after the surface are greater than those at the surface, the optical disc is determined to be an optical disc with a largest capacity. It is determined whether or not there is a reflective layer at a depth equal to or less than 0.1 mm. If there is no reflective layer thereat, it is determined whether or not there is a reflective layer at a depth of 0.6 mm. If there is a reflective layer thereat, the type of the reflective layer is determined based on TE and RF signals with blue light. If the blue light is not adaptable to the layer, red light is emitted, and replay of the recording layer at a depth of 0.6 mm is performed.

Abstract: A beam shaping lens for shaping an incident beam having an elliptic cross section into an outgoing beam having a substantially circular cross section includes a first plane which is a cylindrical surface having a generating line curving to form a non-circular cylindrical surface as an incidence side of the incident beam and a second plane which is a circular cylindrical surface as an outgoing side of the outgoing beam. The distance between both ends of the generating line of the circular cylindrical surface is larger than the distance between both ends of the generating line of the non-circular cylindrical surface.

Abstract: The present invention provides an optical structure of an optical pickup for adjusting the exit light quantity of a light source so as not to have adverse effect on reliability of semiconductor laser to be suited to the quantity of light, in consideration of difference in reflectivity of optical discs used in recording or reproducing. With this configuration, when composing a compatible optical pickup for recording or reproducing BD and HD DVD by using light diffraction means of diffraction type, the reliability of semiconductor laser used as light source may be enhanced with its diffraction efficiency.

Abstract: An optical pickup is provided for directing a blue-violet laser beam to access a first information recording medium covered with a first transparent substrate or a second information recording medium covered with a second transparent substrate, which includes a light path switching unit disposed either between a light source and a coupling lens or between the coupling lens and an objective lens for switching the blue-violet laser beam between a first light path and a second light path. The coupling lens is arranged to convert the laser beam reflected on the first or second information recording medium to a converged light. The converged light of the laser beam is then received by a photo detector.

Abstract: When performing a read or write operation on an optical disc with information storage layers, this compatible optical head with a two-focus lens can reduce interference caused by an unnecessary diffracted light reflected from a non-target layer and not contributing to reading or writing. The head reads and/or writes information from/on storage media, including first and second media with different protective substrate thicknesses, by irradiating a given one with a laser beam and includes: a diffraction element that diffracts the beam to produce diffracted light of multiple orders; an objective lens for converging nth and mth order ones of the light on the respective storage layers of the first and second media; a photodetector that receives the beam reflected from the medium and condensed; and a light shielding portion for preventing a portion of the beam reflected from the storage layer of the second medium and including its optical axis from reaching the photodetector.

Abstract: [Problem] The present invention provides an afocal lens for an optical head that can ensure WD while satisfying NA, the optical head, an optical disc apparatus, a computer, an optical disc player, and an optical disc recorder. [Solution] Using a blue-violet laser beam source with wavelength of about 400 nm, and in an optical head compatible to optical discs having different protective substrate thickness, an afocal lens 105 that expands a diameter of light flux of light from a collimating lens and emits the light as substantially parallel light to an objective lens is provided between the collimating lens 104 and the objective lens 106. The configuration makes it possible to ensure WD while satisfying NA.

Abstract: An optical head apparatus is made to be downsized while obtaining an sufficient driving force of an objective lens actuator. The optical head apparatus includes a first optical system including a first objective lens for focusing a light beam upon an optical disc; a second optical system including a second objective lens for focusing a light beam upon an optical disc having an information recording density smaller than the optical disc which the first optical system irradiates upon, the second objective lens having a numerical aperture smaller than the first objective lens; and an up-orienting prism including a first reflecting surface for deflecting a light beam to an optical axis of the first objective lens in the first optical system, and a second reflecting surface for deflecting a light beam to an optical axis of the second objective lens in the second optical system.

Abstract: In the present invention, at the time of pulling a focus on an information recording surface of a disc, a focus servo is first pulled in a substrate surface of the disc, and with the servo in a settled state, a driving signal necessary for following surface wobble is stored, and a focus is pulled in the information recording surface of the disc based upon a signal superimposed with the driving signal and a focus search driving signal.

Abstract: 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. An information recording medium includes a first information recording layer and a second information recording layer, to/from which information is recorded or reproduced using laser beam. The first information recording layer is formed at a laser beam entrance surface, and is configured so that information can be recorded thereupon and/or reproduced therefrom using a first objective lens having a first numerical aperture NA1 and laser beam of a first wavelength ?1. The second information recording layer is formed so as to have a distance to the laser beam entrance surface is 0.05 mm to 1.

Abstract: The present invention aims to provide an optical head and an optical disk device capable of suitably detecting tracking error signals for different types of optical discs. A polarizing hologram element includes a first area and a second area adjacent to the first area in an area where a beam reflected and diffracted by a BD passes. The first area includes a first transmission area for transmitting many 1st-order diffracted lights from the BD, a second transmission area adjacent to the first transmission area and closer to an optical axis than the first transmission area, and a third transmission area adjacent to the first and second transmission areas. The second area includes a fourth transmission area for transmitting many 1st-order diffracted lights from the BD, a fifth transmission area adjacent to the fourth transmission area and closer to the optical axis than the fourth transmission area, and a sixth transmission area adjacent to the fourth and fifth transmission areas.

Abstract: An antenna apparatus includes a monopole antenna forming an antenna element having a metal shell body, and the antenna element has an approximately conical part, a vertex of which is on the side of a power supply part.

Abstract: An objective lens actuator is provided which includes two objective lenses mounted on a movable body, and which is capable of preventing the movable body from coming into contact or collision with a disk and whose thickness becomes thinner. When a light beam is concentrated and focused on a high-density optical disk, D1 represents the distance between the disk surface and the part of the movable body in the closest position to the disk; when a light beam is concentrated and focused on a CD, D2 represents the distance between the disk surface and the part of the movable body in the closest position to the disk; when a light beam is concentrated and focused on a DVD, D3 represents the distance between the disk surface and the part of the movable body in the closest position to the disk; and the following relational expression (1) is satisfied, D1<D2<D3??(1).

Abstract: A diffraction element includes a light-transmittable member and a diffraction grating formed on at least one face of the light-transmittable member. When a first laser beam having a first wavelength ?1 and a second laser beam having a second wavelength ?2 are transmitted through the diffraction element at first and second diffraction efficiencies, respectively, the diffraction element functions to equalize the first and second diffraction efficiencies to each other by only the one face of the diffraction element. The diffraction grating has a first phase modulation amount ø1 for the first laser beam and a second phase modulation amount ø2 for the second laser beam and the first and second phase modulation amounts ø1 and ø2 are, respectively, approximate to (2?N1±?ø) and (2?N2±?ø) in which “N1” and “N2” are natural numbers and “?ø” is a phase variation amount.

Abstract: An antenna apparatus includes a monopole antenna forming an antenna element having a metal shell body, and the antenna element has an approximately conical part, a vertex of which is on the side of a power supply part.

Abstract: The present invention is provided with a detection region for detecting light that is reflected from a first or a second information recording medium and that passes through an optical element. The first information recording medium and the second information recording media are multi-layer disks that have at least two layers, and the detection region includes a detection region (41) for detecting first order and above diffracted light that has a first wavelength, and a detection region (42) for detecting first order and above diffracted light that has a second wavelength.

Abstract: A beam shaping lens for shaping an incident beam having an elliptic cross section into an outgoing beam having a substantially circular cross section includes a first plane which is a cylindrical surface having a generating line curving to form a non-circular cylindrical surface as an incidence side of the incident beam and a second plane which is a circular cylindrical surface as an outgoing side of the outgoing beam. The distance between both ends of the generating line of the circular cylindrical surface is larger than the distance between both ends of the generating line of the non-circular cylindrical surface.

Abstract: A diffraction element includes a light-transmittable member and a diffraction grating formed on at least one face of the light-transmittable member. When a first laser beam having a first wavelength &lgr;1 and a second laser beam having a second wavelength &lgr;2 are transmitted through the diffraction element at first and second diffraction efficiencies, respectively, the diffraction element functions to equalize the first and second diffraction efficiencies to each other by only the one face of the diffraction element. The diffraction grating has a first phase modulation amount ø1 for the first laser beam and a second phase modulation amount ø2 for the second laser beam and the first and second phase modulation amounts ø1 and ø2 are, respectively, approximate to (2&pgr;N1±&Dgr;ø) and (2&pgr;N2±&Dgr;ø) in which “N1” and “N2” are natural numbers and “&Dgr;ø” is a phase variation amount.

Abstract: It is intended to provide an optical fiber-cutting method and an optical fiber-cutting machine, by which an optical fiber can be cut smoothly and perpendicularly to the axis of the optical fiber. A ferrule 21 is held by a holder 14 which is supported in a slantingly movable fashion relative to the main body 12 of a cutting machine 11, and an end portion of the optical fiber 20 projecting from an end face of the ferrule 21 is held by a clamp 16 to apply a pulling force to the optical fiber. The holder 14 is slanted to bend the optical fiber 20, and a cutting blade 28 is moved in an arc line along the circumference of a basal portion at the inner side of the bending portion of the optical fiber 20 while butting the cutting blade 28 to the optical fiber 20, to make a cut 20a of an arc shape, and then the holder 14 is slanted toward the direction opposite to the above direction to bend the optical fiber 20 toward the direction opposite to the above direction, thereby cutting the optical fiber 20.