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: An optical pickup includes a lens holder; an objective lens provided on the lens holder and having an effective region for collecting light from a light source and an edge located outer to the effective region; and a lens protector provided on the lens holder. The lens protector protrudes toward an optical disc more than the objective lens. The edge of the objective lens includes a convexed portion protruding toward the optical disc. An apex of the effective region of the objective lens protrudes toward the optical disc more than the convexed portion of the edge. A straight line connecting a part of the edge of the objective lens and a part of the lens protector is closer to the optical disc than the apex of the effective region of the objective lens.

Abstract: An optical disk driving apparatus includes an optical head device having a laser light source, a converging optical system converging a light beam emitted by the laser light source onto an optical disk, a photo detector receiving reflected light reflected by the optical disk, and an aberration correcting optical system controlling aberration of the converging optical system; a motor rotating the optical disk; and a control section receiving a signal from the photo detector, wherein the converging optical system has an objective lens formed using resin as a main material, the aberration correcting optical system has a spherical aberration correcting element correcting spherical aberration, and the control section evaluates quality of a reproduction signal for information in the optical disk by using the reflected light received by the photo detector, and utilizes a result of the evaluation to perform closed loop control on the spherical aberration correcting element.

Abstract: In an optical head device which performs recording/reading of data in/from a high-density optical disc using an objective lens with a large NA, a saw-tooth shape diffraction element is used for also performing recording/reading of data in/from a conventional optical disc, such as DVD, CD, or the like. A step difference that produces an optical path length for blue light which is equal to or longer than the wavelength of the blue light and optical path lengths for red and infrared light which are shorter than the wavelengths of the red and infrared light is utilized so as to exert an inverse action on the blue light to those exerted on the red and infrared light. The effect of increasing the working distances for CD and DVD enables multiple compatibility. The optical element is integrally combined with the objective lens to perform a tracking servo following operation.

Abstract: An objective lens, an optical head, an optical disk apparatus and an information processing apparatus which can suppress deterioration of a focal spot caused by a drop in the diffraction efficiency. Inner and outer circumference areas converge a laser beam, out of laser beams having a wavelength ?1 which are diffracted by the inner and outer circumference areas, on a first information recording medium; the inner circumference area and a mid-circumference area converge a laser beam, out of the laser beams having a wavelength ?2 which are diffracted by the inner circumference area and the mid-circumference area, on a second information recording medium; and the diffraction efficiency of the laser beam having the wavelength ?2 is greater than the diffraction efficiency of the laser beam having the wavelength ?1.

Abstract: An information recording medium includes a first information recording layer and a second information recording layer. 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 numerical aperture NA1 and laser beam of a wavelength ?1. The second information recording layer is formed so as to have a distance to the laser beam entrance surface of 0.05 mm to 1.2 mm and is configured so that information can be recorded thereupon and/or reproduced therefrom using a second objective lens having a numerical aperture NA2 and laser beam of a wavelength ?2. When a diffraction limit ?2, determined by numerical aperture NA2 and wavelength ?2, is taken as ?2=0.61×?2/NA2, a track pitch Tp1 of a track formed on the first information recording layer is Tp1<?2.

Abstract: A disclosed objective lens includes: a lens having an entrance surface and an emission surface; and an anti-reflection coat formed on the emission surface, wherein a transmittance T1—0 [%] of the anti-reflection coat when an incident angle of a first laser beam having a first wavelength ?1 (390 nm??1?430 nm) is 0°, and the transmittance T1—40 [%] of the anti-reflection coat when the incident angle of the first laser beam is 40° satisfy 0.95?T1—0/T1—40?1.05, and a transmittance T2—0 [%] of the anti-reflection coat when an incident angle of a second laser beam having a second wavelength ?2 (630 nm??2?680 nm) is 0° and a transmittance T2—40 [%] of the anti-reflection coat when the incident angle of the second laser beam is 40° satisfy 0.85?T2—0/T2—40?0.97.

Abstract: An optical disc type is determined by detecting focus error signals and an amount of returned light, while (i) emitting light having a wavelength maximizing a focal length and (ii) moving an objective lens in a direction of an optical axis. If an S shape and AS immediately after a surface are greater than those at the surface, the optical disc is determined to have a largest capacity. It is also determined whether there is a reflective layer at a depth equal or less than 0.1 mm, if not, then it is determined whether there is a reflective layer at a depth of 0.6 mm. If there is a reflective layer at the depth of 0.6 mm, then the type of the reflective layer is determined based on TE/RF signals, using blue light. If the blue light is not adaptable, red light is emitted to replay at a depth of 0.6 mm.

Abstract: In an electronic device including a temperature sensor and an electronic component which is a heat generation source, the temperature is measured while the influence of heat from the electronic component is reduced. The electronic device includes: a base formed of a resin material; a board which is disposed at one side of the base, and includes an electronic component and a temperature sensor; and a heat sink which is disposed at the other side of the base for dissipating heat generated by the electronic component. The heat sink includes an extension part extending from the other side of the base toward a position of the board at which the electronic component is provided.

Abstract: An optical disk driving apparatus includes an optical head device having a laser light source, a converging optical system converging a light beam emitted by the laser light source onto an optical disk, a photo detector receiving reflected light reflected by the optical disk, and an aberration correcting optical system controlling aberration of the converging optical system; a motor rotating the optical disk; and a control section receiving a signal from the photo detector, wherein the converging optical system has an objective lens formed using resin as a main material, the aberration correcting optical system has a spherical aberration correcting element correcting spherical aberration, and the control section evaluates quality of a reproduction signal for information in the optical disk by using the reflected light received by the photo detector, and utilizes a result of the evaluation to perform closed loop control on the spherical aberration correcting element.

Abstract: An optical pickup device preventing damage or performance degradation of a second optical system. The optical pickup device includes first laser light source emitting a first light beam having a first wavelength, a first optical system guiding the first light beam emitted from the first laser light source to a first optical disc. Further, the optical pickup device includes a DVD integration unit emitting a second light beam having a second wavelength different from the first wavelength, a second optical system guiding the second light beam emitted from the DVD integration unit to a second optical disc different from the first optical disc, and a filter disposed at a position blocking incident light, of an unwanted light beam having the first wavelength and derived from the first optical system, from entering into the second optical system, so as to block the first light beam having the first wavelength.

Abstract: In an optical head device which performs recording/reading of data in/from a high-density optical disc using an objective lens with a large NA, a saw-tooth shape diffraction element is used for also performing recording/reading of data in/from a conventional optical disc, such as DVD, CD, or the like. A step difference that produces an optical path length for blue light which is equal to or longer than the wavelength of the blue light and optical path lengths for red and infrared light which are shorter than the wavelengths of the red and infrared light is utilized so as to exert an inverse action on the blue light to those exerted on the red and infrared light. The effect of increasing the working distances for CD and DVD enables multiple compatibility. The optical element is integrally combined with the objective lens to perform a tracking servo following operation.

Abstract: An objective lens unit according to the present invention includes a first objective lens 41; and a first lens holder 2 for supporting the first objective lens 41. The first lens holder 2 is formed of a material which transmits ultraviolet. Preferably, the first lens holder 2 includes a through-hole, having first and second openings 2a and 2b, through which light incident on the first objective lens 41 passes, and an opening limiting section 3 provided along a circumferential direction of the through-hole and projecting toward a central axis of the through-hole. The first objective lens 41 is supported so as to block the first opening 2b. The opening limiting section 3 guides light incident thereon from the second opening 2a in a direction away from an optical axis of the first objective lens.

Abstract: An optical pickup includes a lens holder; an objective lens provided on the lens holder and having an effective region for collecting light from a light source and an edge located outer to the effective region; and a lens protector provided on the lens holder. The lens protector protrudes toward an optical disc more than the objective lens. The edge of the objective lens includes a convexed portion protruding toward the optical disc. An apex of the effective region of the objective lens protrudes toward the optical disc more than the convexed portion of the edge. A straight line connecting a part of the edge of the objective lens and a part of the lens protector is closer to the optical disc than the apex of the effective region of the objective lens.

Abstract: In an optical head device which performs recording or reading of data in/from a high-density optical disc using an objective lens with a large NA, a saw-tooth shape diffraction element is used for also performing recording or reading of data in/from a conventional optical disc, such as DVD, CD, or the like. A step difference that produces an optical path length for blue light which is equal to or longer than the wavelength of the blue light and optical path lengths for red and infrared light which are shorter than the wavelengths of the red and infrared light is utilized so as to exert an inverse action on the blue light to those exerted on the red and infrared light. The effect of increasing the working distances for CD and DVD enables multiple compatibility. The above optical element is integrally combined with the objective lens to perform a tracking servo following operation.

Abstract: To provide an optical pickup and an optical information device, capable of obtaining excellent signal characteristics for an optical disk on and/or from which recording and/or reproducing are performed using a laser. The optical pickup includes an optical detector, a support holder for holding the optical detector, and an optical base for fixing the support holder. The support holder has at least two notches at its both ends, the optical base has convex portions corresponding to the notches of the support holder, the optical base and the support holder are fixed by photo-curable adhesives for bonding the convex portions and the support holder to each other, and the shortest distance between the side faces of the convex portions, which do not face each other, is equal to or less than the width of the support holder in the direction of right and left ends.

Abstract: An objective lens, an optical head, an optical disk apparatus and an information processing apparatus which can suppress deterioration of a focal spot caused by a drop in the diffraction efficiency are provided.

Abstract: An information recording medium includes a first information recording layer and a second information recording layer. 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 numerical aperture NA1 and laser beam of a wavelength ?1. The second information recording layer is formed so as to have a distance to the laser beam entrance surface of 0.05 mm to 1.2 mm and is configured so that information can be recorded thereupon and/or reproduced therefrom using a second objective lens having a numerical aperture NA2 and laser beam of a wavelength ?2. When a diffraction limit ?2, determined by numerical aperture NA2 and wavelength ?2, is taken as ?2=0.61×?2/NA2, a track pitch Tp1 of a track formed on the first information recording layer is Tp1<?2.

Abstract: An optical head according to the present invention includes: a first light source that emits light with a first wavelength; a beam splitter that splits the light emitted from the first light source into a first light beam traveling in a first direction and a second light beam traveling in a second direction different from the first direction; a first collimator lens for changing degrees of divergence of the first light beam; a first mirror that changes the traveling directions of the first light beam, of which the degrees of divergence have been changed; a first objective lens for converging the first light beam, which has had its traveling directions changed, toward a storage layer of a first optical disk; a mover that holds the first objective lens; a first photodetector that receives the first light beam reflected from the storage layer of the first optical disk and converts it into an electrical signal; a condenser lens for condensing the second light beam; and a second photodetector that receives the sec

Abstract: A small optical pickup of wide spherical aberration correction range includes a rising mirror for perpendicularly deflecting a light beam and guiding the light beam to an objective lens; a spherical aberration correction lens having one surface formed to a larger curvature than the other surface; a lens holder for holding the correction lens so that the surface of large curvature projects towards the rising mirror side; an axially extending guide member; and a slidable part slidable along the guide member. The projecting portion of the slidable part is configured to be fitted within the side surface of the reflecting surface of the rising mirror, and the projecting portion from the lens holder of the spherical aberration correction lens overlaps the reflecting surface of the rising mirror when the spherical aberration correction lens approaches the rising mirror the most.