Abstract: An optical disc apparatus and method for recording and reproducing information to/from an optical disc, including discrimination of the optical disc, reading control information in an un-recordable area formed in an inner periphery of the optical disc, conducting focus control based on a focus error signal in a recordable area formed outside of the un-recordable area, and determining an optimum offset value of the focus error signal in the recordable area. Further, adjustment in amplitude of a reproduced signal from an inner periphery of the recordable area is conducted, test-writing in the inner periphery of the recordable area is conducted, test-writing in an outer periphery of the recordable area is conducted, and adjustment in amplitude of a reproduced signal from the outer periphery of the recordable area is conducted. The respective operations are conducted sequentially so as to make the optical disc in a reproducible and recordable condition.

Abstract: A method for reproducing information from an optical medium including a substrate with grooves and lands serving as recording tracks alternately formed on the substrate in a radial direction, the recording tracks are divided into recording units in the circumferential direction and each recording unit has a prepit area in a non-groove portion of the substrate including a first prepit representative of VFO information and a second prepit representative of address information. The first prepit and second prepit are located on both sides of a center line of one track and formed on each side of the center line of the one track so as to be shared with an adjacent track adjacent the one side of the center line of the track, and every prepit does not exist at opposing positions on both sides of the center line of one track. Information recorded on the optical medium is reproduced.

Abstract: An optical recording/reproducing apparatus for recording/reproducing information on a medium including a light source, an optical system for focusing and irradiating a light beam generated by the light source on the medium, a photodetector for detecting a reflected beam from the medium, and a circuit for reproducing information by using a signal from the photodetector. The medium includes a substrate with grooves and lands alternately formed on the substrate in a radial direction. The grooves and the lands both serve as recording tracks with the recording tracks being divided into recording units in the circumferential direction. Each recording unit has a prepit area in a non-groove portion of the substrate with a first prepit being represented as VFO information in the prepit area and a second prepit being represented as address information in the prepit area.

Abstract: An optical disc apparatus having at least two optical condenser lens for recording and reproducing information of an optical disc, comprising: means for discriminating the optical disc; means for reading control information in a ROM area which is formed in an inner periphery of said optical disc; means for conducting focus control in a RAM area which is formed outside of said ROM area; means for conducting adjustment in amplitude of a reproduced signal from an inner periphery of said RAM area; means for conducting a pre-writing (a sample-writing); means for conducting test-writing in the inner periphery of said RAM area; means for conducting test-writing in an outer periphery of said RAM area; and means for conducting adjustment in amplitude of a reproduced signal from the outer periphery of said RAM area, wherein said means conducts the respective operations sequentially, thereby making said optical disc in reproducible and recorable condition, with a short time period and with a smooth confirmation operatio

Abstract: An information recording/reproducing apparatus for recording/reproducing information into and from an optical information recording medium, wherein the information of a plurality of sectors is recorded as one recording unit. A recoding area of the recording medium is constructed with a plurality of zones and each zone is different in a sector number per one round of track. A number of the recording units for conducting a verify control for each of the zones is changed on the basis of a number of sectors per one round of track and a number of sectors for turning back by the one round of track.

Abstract: A beam is irradiated to an information recording medium having land tracks and groove tracks alternately formed on a track formed in turn on an information recording surface thereof and pre-pits so pre-formatted as to deviate from the center of the track, a return beam of the irradiated beam is received by detectors split into two parts in a track direction to obtain a differential signal, the pre-pit is detected from this differential signal and control of recording and reproducing processings is executed by using the pre-pit detection signal so obtained as the reference.

Abstract: An information recording medium having spiral or concentric-shaped groove structure along a track formed on a disk-like substrate. The medium has the groove structure wobbled in a radius direction of the medium and the track is divided into a plurality of recording units in the track direction by at least one radial boundary. At least two adjacent recording units in the track direction of the medium comprise one zone and the medium includes a plurality of the zones. The groove structure included in the adjacent recording units within any zone has substantially the same number of wobbling.

Abstract: An optical recording/reproducing apparatus for recording/reproducing information on a medium including a light source, an optical system for focusing and irradiating a light beam generated by the light source on the medium, a photodetector for detecting a reflected beam from the medium, and a circuit for reproducing information by using a signal from the photodetector. The medium includes a substrate with grooves and lands alternately formed on the substrate in a radial direction. The grooves and the lands both serve as recording tracks with the recording tracks being divided into recording units in the circumferential direction. Each recording unit has a prepit area in a non-groove portion of the substrate with a first prepit being represented as VFO information in the prepit area and a second prepit being represented as address information in the prepit area.

Abstract: An information recording medium having a spiral or concentric-shaped groove structure along a track formed on a disk-like substrate. The medium has the groove structure wobbled in a radius direction of the medium and the track is divided into a plurality of recording units in the track direction by at least one radial boundary line. At least two adjacent recording units in the radius direction of the medium comprise one zone, and the groove structure included in the respective recording units within one zone has at least one of substantially the same number of wobbling and the wobbling cycle.

Abstract: An optical disk recording medium including a substrate in the form of a substantially circular disk. Grooves and lands are alternately formed on the substrate in a radial direction with the grooves and lands both serving as recording tracks. The recording tracks are divided into recording units in the circumferential direction with each recording unit having a prepit area in a non-groove portion of the substrate. Plural pairs of first and second prepit portions are provided in the prepit area of each recording unit with first prepit portion being represented as VFO information and the second prepit portion being represented as address information.

Abstract: An information recording medium having spiral or concentric tracks with a plurality of grooves and lands formed on a disk-like substrate. Each of the tracks is divided into a plurality of recording units and each of the recording units includes a blank portion in a circumferential direction of the track. The track is formed with a wobble in a radial direction and each of the recording units has a length which is an integer multiple of a cycle of the wobble.

Abstract: An optical recording/reproducing method and apparatus for use with an optical recording medium to which grooves and lands are formed on a substrate. Information recording areas are formed in association with both a groove and a land and an address area is formed at the information recording area preceding the groove and the land. VFO and address information are represented by pits which are disposed on an extension of the boundary between said groove and said land. The pits represents the VFO and address information and are disposed to satisfy such requirements that the pits are disposed alternately on both sides of an extension of the center line of one groove, that the pits are disposed alternately on both sides of an extension of the center line of one land, that the pits do not exist on both sides of a position on an extension of the center line of the groove and that the pits do not exist on both sides of a position on an extension of the center line of the land.

Abstract: A beam is irradiated to an information recording medium having land tracks and groove tracks alternately formed on a track formed in turn on an information recording surface thereof and pre-pits so pre-formatted as to deviate from the center of the track, a return beam of the irradiated beam is received by detectors split into two parts in a track direction to obtain a differential signal, the pre-pit is detected from this differential signal and control of recording and reproducing processings is executed by using the pre-pit detection signal so obtained as the reference.

Abstract: An optical disk signal processing apparatus retains compatibility with the conventional continuous servo recording technique, and reduces the amount of noise included in a signal played back from the optical disk without the need to decrease the size of the area for recording data, resulting in a drastically increased signal-to-noise ratio. The optical disk signal processing apparatus has a light source, an optical system for leading a light beam generated by the light source, an optical device for converging the light beam output by the optical system and applying the converged beam to the rotating optical disk, a signal detecting optical system for detecting a signal reflected by the rotating disk through the optical device, and a light detecting instrument for converting light produced by the signal detecting optical system into an electrical signal and a data detecting circuit.

Abstract: For a disk of a land/groove scheme with land tracks and grooves appearing alternately, in order to enable stable and reliable reproduction of information as recorded on a disk by stably and reliably detecting a specific position at which a land track and groove change therebetween, a technique is employed for detecting the position whereat one land track is changed to a groove, or vice versa, by utilizing an HPP signal rather than an RF signal in cases where an optical head 103 attempts to reproduce certain information at the pit formation position of a disk 101. In addition, detect the polarity--positive or negative--of a pit signal appearing in the HPP signal, and then detect the position whereat the land track and groove change therebetween based on the position at which the order or sequence thereof changes, thereby permitting effectuation of optical head's tracking control and focus control by a method suitable for its respective parts.

Abstract: A high density optical recording medium having wide-width grooves capable of reliable tracking is provided. The optical recording medium is formed with the wide-width grooves 12 in which a width g of the groove 12 is larger than a width L of a land between the grooves. The lands 11 and the grooves 12 are formed so that a track pitch Tp is less than 1 .mu.m, and a land height h from a groove bottom surface 13 satisfies [(.lambda./(8n)).multidot.Ltan.theta.]/[Ltan.theta.-(.lambda./(8n))].ltore q.h.ltoreq.[(.lambda./(5n)).multidot.Ltan.theta.]/[Ltan.theta.-(.lambda./(5 n))] with respect to a wavelength .lambda. of a reproducing light beam and a refractive index n of a substrate. An angle of inclination of a groove side wall is represented by .theta., and the refractive index of the substrate is represented by n.

Abstract: An optical disk signal processing apparatus retains compatibility with the conventional continuous servo recording technique, and reduces the amount of noise included in a signal played back from the optical disk without the need to decrease the size of the area for recording data, resulting in a drastically increased signal-to-noise ratio. The optical disk signal processing apparatus has a light source, an optical system for leading a light beam generated by the light source, an optical device for converging the light beam output by the optical system and applying the converged beam to the rotating optical disk, a signal detecting optical system for detecting a signal reflected by the rotating disk through the optical device, and a light detecting instrument for converting light produced by the signal detecting optical system into an electrical signal and a data detecting circuit.

Abstract: A recording medium having a plurality of recording tracks with address information allocated thereon and a method for allocation of the address information. The recording medium and method includes disposing first address information disposed on one side of the center line of one track, and disposing second address information disposed on another side of the center line of the one track. The one track and one adjacent track on the one side of the center line of the one track share the first addressing information, the one track and another adjacent track on the another side of the center line of the one track share the second address information, and the combination of the first and second address information provide a unique address for at least a portion of the one track.

Abstract: A disk-like information recording medium includes recording areas provided in both of a groove portion and a land portion. The information recording medium is divided into groups of a plurality of areas, each track is divided into circular arc-shaped sectors having the same central angle arranged to be radial in the radius direction, identification information is provided at every sector, each track is divided into groups in such a manner that lengths of the circular arc-shaped sectors become almost constant among the groups, and the groove portion and the land portion are wobbled in the radius direction of the information recording medium. When the groove portion information track and the land portion information track which are the recording portions are wobbled in the radius direction, position information can be reliably obtained from the recording portions, and hence recorded information can be accessed reliably.

Abstract: A disk-like information recording medium includes recording areas provided in both of a groove portion and a land portion. The information recording medium is divided into groups of a plurality of areas, each track is divided into circular arc-shaped sectors having the same central angle arranged to be radial in the radius direction, identification information is provided at every sector, each track is divided into groups in such a manner that lengths of the circular arc-shaped sectors become almost constant among the groups, and the groove portion and the land portion are wobbled in the radius direction of the information recording medium. When the groove portion information track and the land portion information track which are the recording portions are wobbled in the radius direction, position information can be reliably obtained from the recording portions, and hence recorded information can be accessed reliably.