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.

Systems and methods for logically organizing data for storage and recovery on a data storage medium using a multi-level format are described. Embodiments include systems and methods for protecting data stored on a data storage medium so that the data may be recovered without errors.

An optical recording medium includes a plurality of information signal layers. The plurality of information signal layers include a recording layer having a first surface that faces a light irradiation surface and a second surface on the side opposite to the first surface, a first dielectric layer that is provided on the side of the first surface, and a second dielectric layer that is provided on the side of the second surface. The second dielectric layer provided in the information signal layer positioned on the innermost side when viewed from the light irradiation surface contains indium oxide and tin oxide. The recording layer provided in the information signal layer positioned on the innermost side when viewed from the light irradiation surface contains an oxide of a metal MA, an oxide of a metal MB, an oxide of a metal MD, and an oxide of a metal ME, the metal MA is at least one selected from the group consisting of Mn and Ni, the metal MB is at least one selected from the group consisting of W, Mo, Zr and Ta, the metal MD is at least one selected from the group consisting of Cu and Ag, the metal ME is Nb, the contents of the metal MA, the metal MB and the metal ME satisfy the relationship of 0.30≤a.sub.1/(b.sub.1+e.sub.1)≤0.41 (where, a.sub.1: atomic ratio [atomic %] of the metal MA with respect to a total amount of the metal MA, the metal MB, the metal MD and the metal ME, b.sub.1: atomic ratio [atomic %] of the metal MB with respect to a total amount of the metal MA, the metal MB, the metal MD and the metal ME, and e.sub.1: atomic ratio [atomic %] of the metal ME with respect to a total amount of the metal MA, the metal MB, the metal MD and the metal ME), and the atomic ratio e.sub.1 of the metal ME with respect to a total amount of the metal MA, the metal MB, the metal MD and the metal ME is 5 atomic % or more and 18 atomic % or less.

An optical information storage medium includes a substrate and a multilayer polymeric film. The multilayer polymeric film has a first surface and an opposite second surface that extend the length of the multilayer polymeric film. The second surface is adhered to a surface of the substrate. The multilayer polymeric film includes a plurality of coextruded alternating polymeric active data storage layers and polymeric buffer layers.

The present technology relates to a signal processing apparatus, a signal processing method, and a program by which, in reproducing transmitted encoded data in real time, buffer overflow can be prevented from occurring on a reception apparatus side even if it is transmitted with a compression rate of the encoded data being varied in a manner that depends on communication condition. Encoded data including transmitted audio data is buffered by a reception buffer. At this time, the quantity of encoded data buffered by the reception buffer is managed in units of processing according to an encoding method. The present technology is applicable to a real-time content reproduction system utilizing a communication system.

An optical disk (100) of the present invention includes (i) a medium information region (101) (a) in which type identification information is recorded by recesses and/or protrusions which are formed by a given modulation method and whose lengths are longer than a length of an optical system resolution limit of a playback device and (b) in which first address information is recorded in a first address data format and (ii) a data region (102) (a) in which content data is recorded by recesses and/or protrusions which are formed by the given modulation method and which include a recess and/or a protrusion whose length is shorter than the length of the optical system resolution limit and (b) in which second address information is recorded in a second address data format.

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.

A write-once type information recording medium according to one aspect of the present disclosure includes at least one recording layer. In the information recording medium, the at least one recording layer has a spiral shape in which a land track and a groove track are alternately arranged as a recording track, the recording track is divided into blocks each of which being minimum unit in which recording is performed, and the information recording medium includes a management information area where management information is recorded and a user data area where user data is recorded. Each of the management information areas of both the land track and the groove track on each recording layer of the at least one recording layer is disposed at a same distance from the center of the information recording medium.

A write-once type information recording medium according to one aspect of the present disclosure includes at least one recording layer. In the information recording medium, the at least one recording layer has a spiral shape in which a land track and a groove track are alternately arranged as a recording track, the recording track is divided into blocks each of which being minimum unit in which recording is performed, and the information recording medium includes a management information area where management information is recorded and a user data area where user data is recorded. Each of the management information areas of both the land track and the groove track on each recording layer of the at least one recording layer is disposed at a same distance from the center of the information recording medium.

The purpose of the present invention is to provide a hologram reproducing apparatus and a hologram reproducing method, which are suitable for reproducing hologram. The purpose can be achieved by means of a hologram reproducing apparatus, which reproduces information signals by irradiating an optical information recording medium with reference light, and a hologram reproducing method for the hologram reproducing apparatus. The hologram reproducing apparatus is characterized in being provided with: a polarization conversion section, which converts polarization of diffracted light that is generated when the optical information recording medium is irradiated with the reference light; a light receiving section, which receives the diffracted light having the polarization thereof converted by means of the polarization conversion section; and a servo signal generating circuit section, which generates signals for moving the optical information recording medium or the polarization conversion section using the diffracted light received by means of the light receiving section.