Ricoh Company, Ltd.

Samsung Electronics Co., Ltd.

Ikuo Aoki

Hiroshi Maegawa

Yoshitaka Takahashi

Kenya Yokoi

An optical disc having track grooves formed in a radial direction of the disc, and with the disc being divided into a plurality of zones, wherein track grooves are formatted into waved patterns, based on a predetermined modulation rule, in the radial direction of the disc to record zone address information for each of the divided zones. The waved pattern may overlap over recorded user data. Each zone has a recording capacity in which an arbitrary recording capacity is added to a data recording capacity needed for each divided zone.

Optical disc

A hologram recording medium in which data is recorded at a high density, the input of a reference beam to an area to which data is not to be recorded of a recording layer is prevented when recording data to the hologram recording medium, and an amount of noise when reproducing the data from the hologram recording medium is reduced. The hologram recording medium includes a light velocity restriction member restricting an incidence area of a hologram recording layer, thus restricting the incidence of a reference beam onto the hologram recording layer, preventing the incidence of the reference beam onto an area to which data is not to be recorded of the hologram recording layer when recording data and reproducing the amount of noise when reproducing data.

Hologram recording medium, recording/reproducing apparatus and method therefor

An optical disc which is a rewritable optical disc using a phase change medium or a magneto-optical (MO) medium, or a write once type optical disc using a pigment based medium, and has a track for recording user data, in which a wobble portion waved in a radial direction of the optical disc and a non-wobble portion that is not waved are provided on the track, first sub-information and second sub-information which are data other than the user data are recorded on the track by being overlapped, by using a combination of the wobble portion and the non-wobble portion, in the first sub-information, the length of at least one of the wobble portion and the non-wobble portion is different when a bit takes a logical value &ldquo;0&rdquo; and when the bit takes a logical value &ldquo;1&rdquo;, and in the second sub-information, the phase of a wave in the wobble portion when a bit takes a logical value &ldquo;0&rdquo; is different from the phase of a wave in the wobble portion when the bit takes a logical value &ldquo;1&rdquo;.

In an optical disc having tracks for recording user data such as a rewritable type optical disc using a phase change medium or a magneto-optical medium, or a write-once type optical disc using a pigment based medium, a wobble portion waved in a radial direction of the optical disc and a non wobble portion which is not waved are provided on the tracks, sub information which is data other than the user data is recorded on the tracks by using a combination of the wobble portion and the non wobble portion, a logic value of each bit is represented by a pair of the wobble portion and the non wobble portion, and the phase of wave in the wobble portion when a bit is a logical value of &ldquo;0&rdquo; and the phase of wave in the wobble portion when a bit is a logical value of &ldquo;1&rdquo; are different.

Optical disc having format suitable for large amount of data and method of making the same

An optical disc and associated recording/reproducing apparatus is described which creates and reads wobbled tracks on the optical disc. Wobbled tracks are formed in correspondence to a wobble signal which is phase modulated with address information. Phase modulation is used to convert the address information to the wobble signal. The carrier to noise ratio (C/N) of the address information is good, and it is possible to shorten the wobbling amplitude of the tracks while maintaining addressing capabilities. It is thus possible to arrange the track pitch in a high density, and increase the recording capacity of the optical disc.

Optical disc and optical disc apparatus for forming wobbled tracks

A trial writing operation is performed on a phase-change optical disc using write and erase light-emitting powers, which together are varied according to predetermined variation ratios respectively. Signals relevant to said trial writing operation are reproduced from said disc. Optimum ones of the write and erase light-emitting powers are determined using the thus-reproduced signals. The predetermined variation ratios for the write and erase light-emitting powers may be the same as each other. Alternatively, the trial writing operation may be performed on a phase-change optical disc using write and erase light-emitting powers which are individually varied according to predetermined variation ratios respectively.

Phase-change optical disc recording method and apparatus, and

In an information recording system, information is recorded, through light from a light source, in a recording medium comprising a recording layer which has a phase reversibly changeable between a crystal phase and an amorphous phase. The light source emits, for forming a record mark in the recording layer, multi-pulse light which includes a head heating pulse, a head cooling pulse and following rear heating pulse and rear cooling pulse in the stated order. The head heating pulse includes a front division and a rear division. The difference in light-emission power between the head heating pulse and an immediately following cooling pulse is larger than the difference in light-emission power between another heating pulse and an immediately following cooling pulse.

Information recording apparatus, method and computer program product

A power control system controls power of light emitted from a light source to a recording medium. The light having a first power is used to erase previous information from the recording medium and the light having a second power is used to record information in the recording medium in a recording operation. The power control system includes a detecting unit for detecting reflected light from the recording medium when the light source emits the light having the first power to erase the information from the recording medium. The detecting unit outputs a reflection signal corresponding to the reflected light. The power control system further has a control unit for controlling the first power of the light emitted from the light source so that a level of the reflection signal output from the detecting means is controlled at a predetermined target level.

Laser light power control system having reflected light detector

Optical information recording medium in which, information of a data format constructed by an ID section and a data section can be recorded and regenerated from both regions of a land portion and a groove portion formed on a disk face. Information such as an address is recorded to the ID section as a format by a PPM recording system when information is recorded to the data section by a PWM recording system. The information recording medium may have a land portion and a groove portion formed in a spiral or concentric shape. A land mark may be formed in a position information section of the land portion and constructed by a pit recorded as position information, and a groove mark may be formed in a position information section of the groove portion. The groove mark may be constructed using an interrupting portion between grooves and recorded as independent position information different from the position information of the land portion.

Optical recording medium having pre-formatted patterns arrange by

It is an object of the present invention to reduce a data error ratio in the mark edge recording method. In this invention, a corrected value of a record pulse is set by checking the data recording characteristics of an optically recording medium. For this reason, it is possible to adjust a length of a record mark to a specified value as well as to suppress errors such as data errors when data is regenerated.

Method for controlling an optical recording device for improved

An optical information recording medium in the form of an magneto-optical recording disk with a sector format preformatted in accordance with a mark edge recording method, wherein two types of preformat patterns are provided for an area VFO2 for a PLL, positioned after an area ID1 or an area ID2 indicating a track number or a sector number, with one pattern being selected from the two types of preformat patterns and being preformatted, depending upon whether a prepit preformatted in the area ID1 or the area ID2 is completed within the area ID1 or the area ID2, or is discontinued in the area ID1 or the area ID2. The optical information recording medium may be in the form of a 90 mm ROM disk or a 90 mm magneto-optical recording disk including a partial ROM section, provided with a sector format which is preformatted in accordance with the mark edge recording method, wherein a specified data pattern is preformatted in an area GAP or wherein a specified data pattern is preformatted in part or all of areas GAP, FLAG, GAP, and ALPC.

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Yokohama, Japan

Ikuo Aoki