Abstract: A disc-shaped optical data recording medium has a signal recording layer for reading and/or writing data using light, and a 10 ?m to 200 ?m thick transparent protective layer disposed over the signal recording layer. The optical data recording medium includes a protrusion projecting from a surface of the transparent protective layer on a light-incidence surface side to which light is emitted to the signal recording layer. The protrusion is disposed in an area between a center hole and a clamping area where the optical data recording medium is held when reading and/or writing data in the signal recording layer.

Abstract: A disc-shaped optical data recording medium has a signal recording layer for reading and/or writing data using light, and a 10 &mgr;m to 200 &mgr;m thick transparent protective layer disposed over the signal recording layer. The optical data recording medium includes a protrusion projecting from the surface of the transparent protective layer on the light-incidence surface side to which light is emitted to the signal recording layer. The protrusion is disposed in an area between a center hole and a clamping area where the optical data recording medium is held when reading and/or writing data in the signal recording layer.

Abstract: An apparatus for driving an objective lens of the present invention includes: a base which is moved along an optical disk; an objective lens disposed so as to be opposed to the optical disk and having an optical axis in a vertical direction with respect to the optical disk, for optically recording information onto the optical disk or optically reproducing information from the optical disk; a holder portion for holding the objective lens; a plurality of elastic arms extending between the base and the holder portion in a tangent direction of the optical disk, for supporting the holder portion movably with respect to the base; and a driving portion for generating an electromagnetic force for moving the holder portion with respect to the base, wherein the elastic arms are disposed away from each other in a vertical direction, the base includes each movable portion for supporting one end of each of the elastic arms, and each of the movable portions is supported at each position in a vertical direction outside of o

Abstract: A light beam emitted from a light source is focused by an objective lens onto an information recording surface of an optical information recording medium. The objective lens has a substantially truncated-cone-shaped portion on its surface on the side of the optical information recording medium. This makes it possible to prevent interference with a DVD-RAM cartridge and ensure optical compatibility with a BD and a DVD.

Abstract: In an objective lens driving device having a movable portion including an objective lens held by a lens holder, a damage prevention system for preventing the objective lens or a disk from being damaged when the objective lens or the lens holder collides with the disk is provided. The damage prevention system is constituted by inserting a protecting member formed of an elastic member in a fitting portion on an upper surface of the lens holder while being deformed. In this manner, it is possible to generate a sufficient holding power with respect to the protecting member without using glue or the like.

Abstract: An apparatus for driving an objective lens of the present invention includes: a base which is moved along an optical disk; an objective lens disposed so as to be opposed to the optical disk and having an optical axis in a vertical direction with respect to the optical disk, for optically recording information onto the optical disk or optically reproducing information from the optical disk; a holder portion for holding the objective lens; a plurality of elastic arms extending between the base and the holder portion in a tangent direction of the optical disk, for supporting the holder portion movably with respect to the base; and a driving portion for generating an electromagnetic force for moving the holder portion with respect to the base, wherein the elastic arms are disposed away from each other in a vertical direction, the base includes each movable portion for supporting one end of each of the elastic arms, and each of the movable portions is supported at each position in a vertical direction outside of o

Abstract: An objective lens driving apparatus is improved in a tracking drive sensitivity, and is capable of suppressing the occurrence of a tilt when a moving member is driven for tracking and focusing motions. To achieve this, the objective lens driving apparatus comprises: a substantially rectangularly shaped focusing coil and a substantially rectangularly shaped tracking coil, both arranged in the same plane, and fixed to a lens holder to drive the lens holder on which an objective lens is held; and a magnet having mutually opposite magnetic poles arranged at positions opposite winding portions of the focusing coil which lie on two sides thereof extending perpendicularly to a focusing direction, and also having mutually opposite magnetic poles arranged at positions opposite winding portions of the tracking coil which lie on two sides thereof extending perpendicularly to a tracking direction.

Abstract: An objective lens assembly includes: at least two groups of lenses having a common optical axis: and at least two lens holders for respectively holding the at least two groups of lenses, wherein each of the lens holders has an end face perpendicular to the optical axis, and the lens holders are positioned such that the end face of one of the lens holders faces the end face of the other lens holder, and a gap between these end faces is filled with an adhesive agent for adhering the lens holders to each other.

Abstract: Optical disks compliant with different standards are recorded or reproduced by a single recording/reproducing apparatus by a first step of determining a substrate thickness of the disk based on a focusing error signal, when a focusing section for bringing the light beam into a focus on the disk is moved in such a way as to approach or withdraw from the recording surface of the disk; a second step of performing any one step of determining the number of recording surfaces of the disk when the focusing section is moved in such a way as to approach or withdraw from the recording surface of the disk, and determining whether or not the disk can be recorded and reproduced using a tracking error signal detected when the light beam crosses the track.

Abstract: An objective lens driving apparatus is improved in a tracking drive sensitivity, and is capable of suppressing the occurrence of a tilt when a moving member is driven for tracking and focusing motions. To achieve this, the objective lens driving apparatus comprises: a substantially rectangularly shaped focusing coil and a substantially rectangularly shaped tracking coil, both arranged in the same plane, and fixed to a lens holder to drive the lens holder on which an objective lens is held; and a magnet having mutually opposite magnetic poles arranged at positions opposite winding portions of the focusing coil which lie on two sides thereof extending perpendicularly to a focusing direction, and also having mutually opposite magnetic poles arranged at positions opposite winding portions of the tracking coil which lie on two sides thereof extending perpendicularly to a tracking direction.

Abstract: An objective lens assembly includes: at least two groups of lenses having a common optical axis; and at least two lens holders for respectively holding the at least two groups of lenses, wherein each of the lens holders has an end face perpendicular to the optical axis, and the lens holders are positioned such that the end face of one of the lens holders faces the end face of the other lens holder, and a gap between these end faces is filled with an adhesive agent for adhering the lens holders to each other.

Abstract: An objective lens driving apparatus is improved in a tracking drive sensitivity, and is capable of suppressing the occurrence of a tilt when a moving member is driven for tracking and focusing motions. To achieve this, the objective lens driving apparatus comprises: a substantially rectangularly shaped focusing coil and a substantially rectangularly shaped tracking coil, both arranged in the same plane, and fixed to a lens holder to drive the lens holder on which an objective lens is held; and a magnet having mutually opposite magnetic poles arranged at positions opposite winding portions of the focusing coil which lie on two sides thereof extending perpendicularly to a focusing direction, and also having mutually opposite magnetic poles arranged at positions opposite winding portions of the tracking coil which lie on two sides thereof extending perpendicularly to a tracking direction.

Abstract: In an objective lens driving device having a movable portion including an objective lens held by a lens holder, a damage prevention system for preventing the objective lens or a disk from being damaged when the objective lens or the lens holder collides with the disk is provided. The damage prevention system is constituted by inserting a protecting member formed of an elastic member in a fitting portion on an upper surface of the lens holder while being deformed. In this manner, it is possible to generate a sufficient holding power with respect to the protecting member without using glue or the like.

Abstract: An object lens driving device of the present invention includes a movable section, supporting sections for supporting the movable section and a base for holding the supporting sections. The movable section includes an object lens for recording and/or reproducing optical information to and/or from a disk-shaped recording medium, a lens holder for holding the object lens and at least four permanent magnets adhered to the lens holder. The supporting sections include at least four metal wires substantially parallel to each other, each wire having a first end fixed to the lens holder and a second end connected to the base, and elastic deformable elements connected to the base and having connecting sections thereof connected to the second end of each respective metal wire.

Abstract: An optical disc clamp mechanism that is capable of selectively playing back either of a compact disc or a mini disc. The clamp mechanism includes a circular disc receiving section for contacting a reference surface of either of the compact disc or the mini disc and further includes a magnetic clamp unit for clamping the mini disc by magnetic attraction with a magnetically attractable member of the mini disc. A first conical or spherical taper cone portion for engaging the center hole of the mini disc is mounted to the disc receiving section and a second conical or spherical taper cone portion for engaging the center hole of the compact disc is mounted to the disc receiving section. The first taper cone portion is located inwardly of the second taper cone portion and protrudes from the second taper cone portion in the axial direction. The magnetic clamp unit further includes a stopper element for preventing detachment of the first and second taper cone portions from the disc receiving section.

Abstract: In a clamp mechanism, an adapter, and an optical disc apparatus for compatibly playing back an MD and a CD having different centering hole diameters and reference heights, a first clamp mechanism has a taper cone section for both the MD and CD, while a second clamp mechanism has an MD turntable and a CD clamper which is driven in contact with the MD turntable while clamping the CD. The adapter is a disc which has a hole having the same inner diameter as that of the centering hole of the MD and a thickness of 0.8 mm, the adapter to be attached to the CD. A first optical disc apparatus has an MD spindle motor and a CD spindle motor, and an optical system including an objective lens is arranged on a Straight line that connects both the spindle motors. A second optical disc apparatus has a spindle motor having an MD turntable and a CD turntable at both its ends.

Abstract: In a clamp mechanism, an adapter, and an optical disc apparatus for compatibly playing back the MD and CD having different centering hole diameters and reference heights, a first clamp mechanism has a taper cone section for both an MD and a CD, while a second clamp mechanism has an MD turntable and a CD clamper which is driven in contact with the MD turntable while clamping the CD. The adapter is a disc which has a hole having the same inner diameter as that of the centering hole of the MD and a thickness of 0.8 mm, the adapter to be attached to the CD. A first optical disc apparatus has an MD spindle motor and a CD spindle motor, and an optical system including an objective lens is arranged on a straight line that connects both the spindle motors. A second optical disc apparatus has a spindle motor having an MD turntable and a CD turntable at both its ends.

Abstract: An optical pickup having an optical disk (22); a laser diode (11); an objective lens for forming a beam spot on the optical disk; an optical element for guiding a beam from the laser diode to the objective lens; a photodetector for converting a reflected beam from the optical disk into an information signal and an error signal; an optical holder to which at least the objective lens is secured; a first circuit board (17) to which at least the laser diode and the photodetector are attached; an optical base to which the first circuit board (17), is secured; at least the laser diode, the optical element and the photodetector being sealed by the optical holder and the optical base so as to form an optical unit; a stationary member; a second circuit board (28) secured to the stationary member; an elastic support member (21) for elastically supporting the optical unit, which is electrically connected to the first and second circuit boards; at least one permanent magnet (23) secured to the optical unit; a first drive

Abstract: Guide parts and driving parts are independently provided for an optical head and a magnetic bias field generator, and a relative position control part controls the relative positions of the two so that the both can access recording medium tracks individually. Furthermore, a magnetic pattern track for use as the detection signal of the absolute position of the magnetic bias field generator to the magneto-optical recording medium is formed on the magneto-optical recording medium itself, and a positioning control part of the magnetic bias field generator using this magnetic pattern track is provided, so that the positioning control of the absolute position of the magnetic bias field generator with respect to the magneto-optical recording medium may be realized.

Abstract: A magneto-optical recording and/or reproducing apparatus includes an optical head for providing a light spot for recording, reproducing and erasing of a magneto-optical disc, a magnetic head which is disposed at a position opposing the optical head with the magneto-optical disc therebetween and which provides a magnetic field for recording and erasing while maintaining a substantially constant distance from the magneto-optical disc by effecting a lift obtained by an air flow generated by the rotation of the disc, a loadbeam which has the magnetic head on its one end and serves to provide a force caused by elastic deformation to the magnetic head to thereby be balanced with the lift thus obtained, and a moving mechanism connected to the loadbeam. Approaching or evading the magnetic head to or from the magneto-optical disc can be realized by deforming the moving mechanism.