摘要:
Provided is a recording and retrieval apparatus for a multi-layer optical disk. A multi-layer optical disk in which a plurality of recording layers and a single servo layer are combined to form a set is used. A spot for the servo layer and a spot for the recording layers are turned on in a time-sharing manner. Servo signal detection areas are formed discretely in the servo layer. The servo signal detection areas and data recording areas are provided so as not to overlap each other when viewed from the spot incident side. Thus, separation of data from each of the layers can be done by even a single photodetector without interference.
摘要:
Provided is an optical disc apparatus including an interference-type optical disk signal detection system, which allows an optical path difference between two kinds of light to be controlled easily, which has a high signal amplification effect, and which is suitable for miniaturization of an optical system. An interference-type optical system is integrally formed to stabilize an optical path difference between signal light and reference light. At the same time, means for controlling an optical path length of the reference light is attached to a reference mirror, and thereby controls signal amplitude so as to be constantly set the maximum in response to a change in the optical path length with time due to a variation in the thickness of a cover layer of an optical disk, a temperature and the like. Moreover, the optical system is miniaturized by using a Twyman-Green type interference optical system.
摘要:
If a large minimum data unit for recorded data is used to record a small data amount of management information, the recording time is long, and furthermore when a WO (write once) is used as the recording medium, the number of recording operations which can be performed is restricted. To solve the above problems, the present invention can record data in a management area in units smaller than ordinary units for recorded data to suitably record information in a limited management area and thereby efficiently use the user data area. At that time, the present invention simplifies interleave processing usually applied to ordinary recorded data, and performs the simplified interleave processing on a data structure (for data of small size) of the present invention so as to ensure the signal processing compatibility between the ordinary data and data having the data structure according to the present invention.
摘要:
In the optical disk apparatus, an arbitrary seed data for randomizing is added to an original data to be recorded on a disk. One-bit randomizing data is determined by operation using one-bit original data or seed data, and plural-bit past randomized data. At the time of descrambling, descrambling is performed without seed data.
摘要:
The amount of focus offset and the amount of spherical aberration correction are adjusted with respect to a disk on which no data is recorded with high precision. The amount of focus offset and the amount of spherical aberration correction are adjusted on the basis of (1) a focus error signal amplitude, (2) a tracking error signal amplitude in a wide track pitch region, and (3) a rectangular waveform wobble signal envelop level.
摘要:
When reproducing a multilayer optical disk using a high-numerical-aperture objective, the period of time required before the disk is reproduced is reduced by discriminating recording layers. A spherical aberration signal is detected as a differential signal between focus position fluctuation signals respectively in a central section and in a peripheral section of a reproduced flux of light. A recording layer is discriminated using a quantity of correction of spherical aberration at a zero-crossing point of a level or a spherical aberration signal associated with the differential signal. After adding the spherical aberration for the correction of the discriminated layer, residual spherical aberration is corrected by feedback control using a residual spherical aberration signal.
摘要:
In a medium having a restriction on its function which has an extremely low overwrite cyclability as compared with a common one, information is arranged so as to allow restricted write and read operations in a commonly current write and read drive, i.e., the medium is subjected to specific formatting. It is possible to perform write and read operations with security. The specific format can be performed with parameters taking the special-purpose using conditions (i.e., overwrite cyclability) into consideration. Consequently, it becomes possible to provide a low-priced information recording medium.
摘要:
An optical recording apparatus having a light source and an optical system. The medium is a substrate in the form of a substantially circular disk with grooves and lands alternately formed on the substrate in a radial direction. The grooves and lands both serve as recording tracks which are divided into recording units in a circumferential direction. Each recording unit has an address area devoid of the grooves including first and second address information. The first address information is formed on a first boundary between one track and an adjacent track on one side of the one track, and the second address information is formed on a second boundary between the one track and an adjacent track on an other side of the one track with the first address information and the second address information not existing at opposing positions on the boundaries of the one track.
摘要:
A recording method for an optical medium having a disk-like substrate with a spiral or concentric-shaped groove structure along a track formed on the substrate. The groove structure is wobbled in a radial direction of the medium and the track is divided into a plurality of units in the track direction by at least one radial boundary line formed by a dropout portion. Identification information is disposed in the track at a head of each recording unit at the dropout portion and the medium is divided into a plurality of zones in a radial direction with a length of a circular arc being substantially the same between the zones in a circumferential direction. At least two adjacent units in the radial direction of the medium comprise one zone. The method includes providing the optical medium, and recording information on the optical medium by irradiating an optical spot thereon.
摘要:
A method of recording information by irradiating a recording track in an information recording medium with light, the information recording medium comprising a plurality of layers for the recording of information by light irradiation. Each of the layers comprises asperities made up of a groove, the groove in each of the multiple layers having wobbles of a first frequency and wobbles of a second frequency that is different from the first frequency within a single track, wherein the first frequency is constant in each of the layers, and wherein a different signal is obtained from the wobbles of the first and second frequencies in each of the plurality of layers.