An optical recording medium includes a plurality of information signal layers on which information signals are to be optically recorded. Among the plurality of information signal layers, the information signal layer closest to the light-receiving surface has a reflectance of more than 4%.

There are provided an optical disk and an optical disk recording method which are capable of stable data reading in a case where a recording linear density is increased. According to an optical disk of the present disclosure, a run-in pattern recorded in a groove track and a run-in pattern recorded in a land track are made different patterns so that no great change is caused in the amplitude of an acquired signal due to interference between adjacent recording patterns, and thus, data may be stably read.

A configuration for preventing a recording error when a data recording process is performed on both lands and grooves of an optical disc is realized. An information processing device includes a data processing unit configured to control a data recording process on both lands and grooves of an optical disc. The data processing unit performs a process of detecting or matching positions at which data recording states of grooves or lands on both sides adjacent to a data recording target land or groove match when data are recorded on the lands or the grooves. The data processing unit performs, for example, a dummy data recording process or a skipping process as the process of matching the data recording states of the grooves or the lands on both sides adjacent to the data recording target land or groove.

Provided is an optical information recording medium including: a continuously wobbling groove formed in advance by a CAV or a zone CAV. Information is allowed to be recorded on the groove and a land adjacent to the groove, address information is recorded by modulating the wobble, the address information includes a sync pattern indicating a position of the address information and address data, and the sync pattern includes a plurality of first wobble patterns and a second wobble pattern between the first wobble patterns, and at least part of intervals of the first wobble patterns are set to unequal intervals.

An information recording method of the present disclosure is an information recording method for recording information on a write-once information recording medium, including one or more recording layers, each of the recording layers being spiral-shaped on which a land track and a groove track are alternately repeated as recording tracks, each of the recording tracks being divided into blocks, each of the blocks being a minimum unit in which recording is performed. The information recording method includes: recording the information on the information recording medium in a unit of each of the blocks; and controlling recording on the information recording medium. In the control step, switching is performed whether to perform recording in a block to be recorded in which the information is to be recorded next among the blocks based on recording conditions of the recording tracks adjacent on both sides of the block to be recorded.

Amplitude or phase modulated uncompensated wobble patterns representing address patterns for track addresses of optical media are generated or applied to the media. A filter is applied to the un-compensated wobble patterns to detect a threshold value to signal the existence of a synchronization pattern. A pair of filters can be used to detect the threshold and a zero-crossing. This methodology can detect the existence and timing of the wobble pattern. This can eliminate the need for a timing recovery subfield in the wobble pattern of the prior art.

A set of first signal light and reference light with a phase difference of almost 0 degree, a set of second signal light and reference light with a phase difference of almost 180 degrees, a set of third signal light and reference light with a phase difference of almost 90 degrees, and a set of fourth signal light and reference light with a phase difference of almost 270 degrees are generated. A first differential signal as a difference between a first light-receiving signal obtained by a first light-receiving element and a second light-receiving signal obtained by a second light-receiving element is calculated, and a second differential signal as a difference between a third light-receiving signal obtained by a third light-receiving element and a fourth light-receiving signal obtained by a fourth light-receiving element is calculated. The first differential signal and the second differential signal are supplied to respective FIR filters. An equalization error is formed from output signals from the FIR filters. Tap coefficients for the FIR filters are controlled to minimize the equalization error.

An optical recording medium includes a plurality of information signal layers on which information signals are to be optically recorded. Among the plurality of information signal layers, the information signal layer closest to the light-receiving surface has a reflectance of more than 4%.

An optical medium reproduction device includes: a detection unit configured to form detection signals of respective channels by dividing a cross-section of a beam returning from the optical medium into a plurality of regions and performing division into at least one channel corresponding to the region at an outer side in a radial direction, at least one channel corresponding to the region that is different in position in a tangential direction, and a channel corresponding to the other regions, and, in a case of forming the detection signals of the channels, form the detection signal of at least one of the channels by weighting and adding a signal in a predetermined region among the plurality of regions; a multi-input equalizer unit configured to include a plurality of equalizer units to which the respective detection signals of the plurality of channels are supplied, and configured to form an equalized signal on the basis of the detection signals of the plurality of channels; and a binarization unit configured to perform a binarization process on the equalized signal to obtain binary data.

The present disclosure relates to a reproduction apparatus. The reproduction apparatus may comprise an optical filter and electric filters. The optical filter may be configured to provide electrical signals corresponding to regions of an optical beam returning from an optical medium, the optical beam being incident on the optical filter, the regions of the optical beam corresponding to different bands in a line density direction and/or a track density direction. The electric filters may be configured to provide outputs based, at least in part, on the electrical signals provided by the optical filter, wherein the reproduction apparatus is configured to obtain a reproduced signal by combining the outputs of the electric filters.