Abstract: 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<?max(2)<420 and 600<?min(2)<750, and reflectivity thereof decreases monotonously.

Abstract: 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 ? (unit: nm) of the laser beam falls within a range of 400<?<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 ? i = 1 n - 1 ? ( 1 - R ( BL ) ? i 100 ) - ? i = 1 n - 1 ? ( 1 - R ( UV ) ? i 100 ) > 0.

Abstract: An objective lens for an optical information recording/reproducing optical system for an optical disc letting a laser beam impinge on a recording layer of the optical disc, and wherein a center wavelength ? (unit: nm) of the laser beam is in a range defined by a condition: 390???420, a base material of the objective lens is made of resin, the resin has a glass transition temperature Tg and light transmissivity T (unit: %) per a path length of 3 mm at a wavelength of 406 nm defined by conditions: Tg?115° C., 85?T?90, same antireflection films or different types of antireflection films are respectively formed on optical surfaces of the objective lens, and each of the antireflection films formed on the objective lens has a thickness of 100 nm or more in a vicinity of an optical axis of the objective lens.

Abstract: An optical disk drive for recording information on a recording surface of an optical disk and reading information recorded in the optical disk is provided. The optical disk drive includes a spindle to rotate the optical disk and a carriage movable in parallel with a tracking direction of the optical disk. The carriage includes a laser light source to emit laser light, a collimator lens to convert divergent light into parallel light and is arranged with an optical center thereof being in a farther and offset position with respect to an optical axis of the laser light, a reflecting mirror to receive and deflect the laser light transmitted through the collimator lens in a direction perpendicular to the recording surface of the optical disk, and an objective lens to converge the laser light deflected by the reflecting mirror on a position corresponding to the recording surface of the optical disk.

Abstract: An objective lens for an optical information recording/reproducing optical system for an optical disc letting a laser beam impinge on a recording layer of the optical disc, and wherein a center wavelength ? (unit: nm) of the laser beam is in a range defined by a condition: 390???420, a base material of the objective lens is made of resin, the resin has a glass transition temperature Tg and light transmissivity T (unit: %) per a path length of 3 mm at a wavelength of 406 nm defined by conditions: Tg?115° C., 85?T?90, same antireflection films or different types of antireflection films are respectively formed on optical surfaces of the objective lens, and each of the antireflection films formed on the objective lens has a thickness of 100 nm or more in a vicinity of an optical axis of the objective lens.

Abstract: 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 ? (unit: nm) of the laser beam falls within a range of 400<?<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. ? i = 1 n - 1 ? ( 1 - R ( BL ) ? i 100 ) - ? i = 1 n - 1 ? ( 1 - R ( UV ) ? i 100 ) > 0.

Abstract: 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<?max(2)<420 and 600<?min(2)<750, and reflectivity thereof decreases monotonously.

Abstract: According to an aspect of the invention, there is provided an optical pick-up for an optical disc drive, which is provided with an objective lens configured to converge a laser beam emitted from a laser source on a recording surface of an optical disc, spherical aberration caused by the objective lens being compensated at a predetermined setting temperature of the objective lens, a heating unit configured to be driven to heat the objective lens, a spherical aberration detection unit which detects amount of spherical aberration caused by the objective lens, and a driving unit that drives the heating unit in accordance with the amount of the spherical aberration detected by the spherical aberration detection unit, the driving unit driving the heating unit when the spherical aberration detected by the spherical aberration detection unit is positive, the driving unit stopping driving the heating unit when the spherical aberration is zero or negative.

Abstract: An optical disk drive for recording information on a recording surface of an optical disk and reading information recorded in the optical disk is provided. The optical disk drive includes a spindle to rotate the optical disk and a carriage movable in parallel with a tracking direction of the optical disk. The carriage includes a laser light source to emit laser light, a collimator lens to convert divergent light into parallel light and is arranged with an optical center thereof being in a farther and offset position with respect to an optical axis of the laser light, a reflecting mirror to receive and deflect the laser light transmitted through the collimator lens in a direction perpendicular to the recording surface of the optical disk, and an objective lens to converge the laser light deflected by the reflecting mirror on a position corresponding to the recording surface of the optical disk.

Abstract: An optical disc drive includes an optical head having a stationary portion and a movable portion. The movable portion supports an objective lens for converging a beam emitted from the stationary portion on an optical disc. The movable portion moves radially across an optical disc in order to irradiate the beam on a desired track of the optical disc. The optical disc drive is further provided with an aberration correcting lens that corrects aberration caused by the objective lens. The aberration correcting lens is mounted on the movable portion so as to be movable in a direction substantially orthogonal to a movable direction of the movable portion, which may parallel or perpendicular to the optical disc. The aberration correcting lens is moved in accordance with a variation of the aberration caused by the objective lens.

Abstract: An optical information processing device, configured to perform operations of reading and writing information on an optical disk, includes a light source configured to emit a laser beam, an image forming unit configured to converge the laser beam emitted by the light source on the optical disk, a first actuating system configured to actuate the image forming unit so as to converge the laser beam in a desired position on the optical disk, an aberration correcting unit configured to correct aberration generated on a light path from the light source to the optical disk, a second actuating system configured to actuate the aberration correcting unit independently of the image forming unit, and a control system configured to control the second actuating system so as to keep a relative position of the aberration correcting unit with respect to the image forming unit constant.

Abstract: There is provided an optical recording media cartridge, which is provided with a case that accommodates the optical recording media and that has an opening, and a shutter that is attached to the case and that is movable between a first position at which the shutter covers the opening and a second position. The optical recording media cartridge is further provided with a shutter lock mechanism that locks the shutter while the shutter is positioned at the first position, and a shutter release mechanism that releases the shutter locked by the shutter lock mechanism by utilizing a magnetic force exerted thereon.

Abstract: An optical disc drive includes an optical head having a stationary portion and a movable portion. The movable portion supports an objective lens for converging a beam emitted from the stationary portion on an optical disc. The movable portion moves radially across an optical disc in order to irradiate the beam on a desired track of the optical disc. The optical disc drive is further provided with an aberration correcting lens that corrects aberration caused by the objective lens. The aberration correcting lens is mounted on the movable portion so as to be movable in a direction substantially orthogonal to a movable direction of the movable portion, which may parallel or perpendicular to the optical disc. The aberration correcting lens is moved in accordance with a variation of the aberration caused by the objective lens.

Abstract: There is provided an optical recording media cartridge, which is provided with a case that accommodates the optical recording media and that has an opening, and a shutter that is attached to the case and that is movable between a first position at which the shutter covers the opening and a second position. The optical recording media cartridge is further provided with a shutter lock mechanism that locks the shutter while the shutter is positioned at the first position, and a shutter release mechanism that releases the shutter locked by the shutter lock mechanism by utilizing a magnetic force exerted thereon.

Abstract: To record information, a recording/reproducing optical system in an optical head irradiates a recording medium with information light and reference light for recording so that two-dimensional image information is recorded on the recording medium by means of interference between the information light and the reference light for recording. To reproduce information, the recording/reproducing optical system irradiates the recording medium with reference light for reproduction, and collects and detects reproduction light occurring from the recording medium. An optical information recording/reproducing apparatus comprises a tilt detector and an image deviation correction circuit. The tilt detector detects a tilt of the recording medium with respect to a predetermined reference position.

Abstract: An optical disc apparatus includes a fixed portion having a light source portion and a movable portion that holds an objective lens and moves along a radial direction of an optical disc. The fixed portion includes the light source portion for selectively emitting short and long wavelength laser beams, and a collimator lens for collimating the laser beams. The objective lens includes a positive refractive lens and a diffractive lens structure formed on a surface of the refractive lens. The diffractive lens structure has wavelength dependence such that spherical aberration varies in the undercorrected direction as wavelength of incident light increases. The objective lens converges the short wavelength laser beam of a predetermined diffraction order onto an informatlon layer of a thin cover type optical disc, and converges the long wavelength laser beam of the identical diffraction order onto an information layer of a thick cover type optical disc.