摘要:
An information recording disc is provided with a magnetic attracting member in the form of metal piece or magnetic material which serves for attracting a disc member for recording, in particular, for optical recording and reproducing of information, to a spindle of a recording and reproducing apparatus. The magnetic attracting member is held in the space of a holder which is fixedly secured to the disc without the magnetic attracting member being fixedly secured to the disc. This arrangement enables a magnetic clamping of the disc member which provides for a decrease of retardation and is suitable for miniaturization of the apparatus.
摘要:
In an optical information processor such as an optical disc apparatus, when a light beam is irradiated to a plurality of tracks on an information recording medium, the plurality of tracks act as a diffraction grating. Areas in which light receiving parts of a light detector are arranged are determined by a track pitch, a wavelength and a numerical aperture of a condenser lens so that the light detector detects only a change in a light intensity due to an interference between a 0-order diffracted light ray and a 1-order diffracted light ray.
摘要:
A substrate of a recording member comprising a hard base, a first organic substance layer which is formed on the base, and a second organic substance layer which is made of a solvent-soluble organic substance and which is formed on a surface of the first organic substance layer opposite to a surface thereof lying in contact with the base. This substrate can be reused.
摘要:
Disclosed is an optical recording and reproducing apparatus comprising a light source directing a light spot toward a recording medium, a detection system detecting light reflected from the recording medium to derive an electrical signal from the reflected light, an information processing circuit modulating the intensity of the light spot according to writing pulses to record information on the recording medium and using the electrical signal to reproduce information from the recording medium, and a tracking servo circuit carrying out tracking servo operation on the basis of the electrical signal and including an extracting circuit connected to a source of extracting pulses having a pulse width at least equal to the writing pulse width so that writing pulse parts contained in the electrical signal are extracted during recording information, whereby a track offset occurring during information recording can be minimized, and the stability of the tracking servo system can be improved.
摘要:
An optical head for reproducing information contained on an optical information disk includes a plurality of light sources and a plurality of light receiving elements in correspondence with the plurality of laser light sources. There is constructed a constitution in which one laser light source in the plurality of laser light sources is constituted by an individual laser diode and which includes a laser module constituted by other laser light sources and the plurality of light receiving elements to thereby enable to realize the small size of the optical head.
摘要:
In a laser module holding a semiconductor laser chip and a reflecting surface, to perform positioning on the semiconductor laser chip with high precision, and reduce the period of production, so as to realize downsizing and cost reduction, reflecting surfaces provided on a silicon substrate has a step portion, and the reflecting surfaces are used as reflecting surface for laser emission light and laser chip positioning surface, for high precision positioning. Further, in a laser module which requires a high level power for recording, slopes opposite to side surfaces of the semiconductor laser chip in a lengthwise direction have a step portion, and in wiring of lower electrodes of the laser chip from the bottom of the sink to an upper portion of the silicon substrate, a slope having an angle with respect to the laser chip lengthwise direction is formed as a gentle slope, then wiring is made via the slope, thus mitigating occurrence of migration.
摘要:
A super high density optical disk apparatus is obtained by using an exchangeable recording medium having a recording capacity of at least 1.5 Gb/in.sup.2 in an optical recording and reading apparatus for recording or reading at least using a laser beam or by using one of an element which can record on a recording medium only once and another element which can record at least two times repeatedly as recording elements to be used.
摘要:
An optical disk recording and reproducing apparatus for recording and reproducing information and which is capable of storing a large amount of information, transferring data at a high speed and supporting SCSI-1 and SCSI-2. The magnetooptical-disk recording and reproducing apparatus is of the same size as that of the 5.25-inch magnetic disk recording and reproducing apparatus. The front panel 1 has the cartridge slot 2 and cartridge ejection button 3 provided thereon so that a cartridge including a disk for recording and reproducing information is inserted in or ejected from the apparatus. The cartridge insertion slot 2 has a double flap provided so that at least one part of the double flap closes the slot, preventing dust from entering through the cartridge slot 2 except when the cartridge is inserted in or ejected from the apparatus. The magnetooptical-disk recording and reproducing apparatus can record information of 1 GB/side or above on the disk.
摘要:
An optical recording control method determines an optimum recording laser power by effecting a test recording before information to be recorded is recorded on a disk. The recording laser power is formed of a plurality of powers. A relationship among the plurality of laser powers is regulated by power level ratios between respective powers, whereby a power used when a laser light is radiated on the disk can be controlled to be constant independent of an ambient temperature and a structure of a disk. Therefore, accurate recording marks can be formed on the disk.
摘要:
An optical recording/reproducing apparatus includes a plurality of semiconductor lasers, an objective lens for focusing light beams from the semiconductor lasers on an optical disk to form a plurality of light spots, and a correction unit for reducing an offset in a tracking signal occurring concomitantly with relative position correction for the light spots. The correction unit includes a rotary wedge-shaped prism disposed in an optical path through which a laser beam incident on the optical disk and a reflection laser beam from a light spot on the disk pass in opposite directions. The shape, refractive index and initial installation angle of the wedge-shaped prism are designed to have predetermined values that cancel the position shift of the laser beam on the objective lens surface occurring concomitantly with deflection of the laser beam.