Sony Corporation

Naohiro Netsu

Kazuhiko Fujiie

Tetsu Watanabe

Yoshitaka Aoki

Yasuaki Maeda

Takuya Kaeriyama

Yotaro Sanada

Yoshio Kusui

Nobuhiko Ando

Tomohiro Koda

An optical recording medium is provided which has a substrate and a signal recording layer provided on the substrate and in which an information signal is recorded in the form of microscopic pits. A light beam is focused on the signal recording layer and some change of the light beam carried by a return light from the signal recording layer is detected to read the information signal recorded on the signal recording layer. The optical recording medium has a diameter of 65 mm or less and a thickness of 0.4 to 0.7 mm. An information signal recording area extends outwardly from a radial position of 12.5 mm or less from the center of the medium. The ratio in area between the information signal recording area and non-signal recording area is 3.4 or more. The storage capacity of this medium is 2 gigabytes or more. The optical recording medium has formed at the center thereof a center hole around which an annular table-abutment convexing to one side of the medium is formed. A magnetic-clamping hub is installed in the center hole and thus the medium is magnetically clamped to a rotation driving mechanism of an optical recording and/or reproducing apparatus. The compactness and high density of recording of the optical recording medium will contribute greatly to a further compact structure of a recording and/or reproducing apparatus in which the medium is to be used.

Optical recording medium and disc cartridge

While supporting an optical disc having a recording density that is higher than conventional optical discs by shortening the wavelength of the emitted light and increasing the numerical aperture (NA) of an objective lens, a reduction in the size of an optical pickup apparatus relative to the size of a disc cartridge that houses the optical disc is achieved. The present invention includes a fixed optical system having a built-in light source, and a movable optical system having an objective lens. A parallel light beam that enters the movable optical system from the fixed optical system enters the movable optical system via a light path that is parallel to the direction in which the objective lens is movable and from the side on which a spindle motor is provided.

Optical pickup apparatus and signal recording and/or reproducing apparatus

A disk cartridge device includes first and second disk cartridges of different sizes for housing therein disks of different disk diameters and a cassette compartment onto which the first and second disk cartridges are selectively loaded, the cassette compartment including a pair of positioning pins having height-deciding bases for properly placing the first disk cartridge and a pair of positioning pins having height-deciding bases for properly placing the second disk cartridge, wherein the first disk cartridge has stepped escape holes formed on its lower surface to enable itself to escape from the positioning pins by which the second disk cartridge is properly positioned in the loading state when positioning holes of the first disk cartridge are properly fitted into positioning pins and the height is properly decided.

Disk cartridge device operative with disk cartridges of different sizes and height

Read-only optical recording medium and disc cartridge

A disk cartridge device includes first and second disk cartridges of different sizes for housing therein disks of different disk diameters and a cassette compartment onto which the first and second disk cartridges are selectively loaded, the cassette compartment including a pair of positioning pins having height-deciding bases for properly placing the first disk cartridge and a pair of positioning pins having height-deciding bases for, properly placing the second disk cartridge, wherein the first disk cartridge has stepped escape holes formed on its lower surface to enable itself to escape from the positioning pins by which the second disk cartridge is properly positioned in the loading state when positioning holes of the first disk cartridge are properly fitted into positioning pins and the height is properly decided.

A magnetic head device comprising a head section for applying a magnetic field to a disk. The head section includes a magnetic field generating section and a slider . The slider supports the magnetic field generating section and may be set in sliding contact with the disk. The magnetic field generating section has a magnetic core and a coil wound around the magnetic core . The section is designed to generate the magnetic field and embedded in and formed integral with the slider . The head section excels in heat-radiating property.

Magnetic head device and recording/reproducing apparatus using the magnetic head device

An optical recording medium is provided which has a substrate and a signal recording layer provided on the substrate and in which an information signal is recorded in the form of microscopic pits. A light beam is focused on the signal recording layer and some change of the light beam carried by a return light from the signal recording layer is detected to read the information signal recorded on the signal recording layer. The optical recording medium has a diameter of 65 mm or less and thickness of 0.4 to 0.7 mm. An information signal recording area extends outwardly from a radial position of 12.5 mm or less from the center of the medium. The ratio in area between the information signal recording area and non-signal recording area is 3.4 or more. The storage capacity of this medium is 2 gigabytes or more. The optical recording medium has formed at the center thereof a center hole around which an annular table-abutment convexing to one side of the medium is formed. A magnetic-clamping hub is installed in the center hole and thus the medium is magnetically clamped to a rotation driving mechanism of an optical recording and/or reproducing apparatus. The compactness and high density of recording of the optical recording medium will contribute greatly to a further compact structure of a recording and/or reproducing apparatus in which the medium is to be used.

Optical recording medium and disc cartridge having 2 GB capacity

A disk cartridge device includes a plurality of disk cartridges with disks having different disk diameters and each being stored in cartridge housings having different sizes, a recording and reproducing device with the plurality of disk cartridges having different sizes selectively mounted, pairs of positioning pins having a base for determining the height for positioning each of the disk cartridges having different sizes onto the recording and reproducing device and positioning holes on one surface of the disk cartridges having different sizes, to be respectively engaged with the pairs of the positioning pins so as to be positioned. The position of the positioning holes of the disk cartridge having a small disk diameter is disposed outside the disk circumference of the disk cartridge having a large disk diameter.

Disk cartridge device for universally mounting and positioning disk cartridges having disks of different size diameters

Disk cartridge apparatus

A disk cartridge and its loading method in which loading recessed portions can easily be secured and mis-loading and mis-insertion of the disk cartridge can be prevented, wherein the disk cartridge has at its left and right side end portions on the insertion side formed as a pair of loading recess portions and one loading recess portion is hidden by a shutter plate that has been placed in the closed state.

Growing community of inventors

Chiba, Japan

Naohiro Netsu