摘要:
An evaluation method for calculating an identification signal by using PRML, comprises a table storing true patterns and ideal signals thereof, false patterns corresponding to the true patterns and ideal signals thereof, and Euclidean distance between the true pattern and the false pattern, a calculating unit, when a recording signal synchronized with an identification signal coincides with any pattern of the table, calculates a distance between Euclidean distance between the ideal signal of the true pattern and a reproduction signal and Euclidean distance between the ideal signal of the false pattern and a reproduction signal, and an evaluation unit which evaluates an identification signal by using an average and standard deviation of difference. A table for patterns is created for a likely mistaken pattern, whereby calculating an evaluation value with high precision, of a signal quality, with a small amount of calculation.
摘要:
This invention relates to a reproduced signal evaluation method of evaluating a reproduced signal reproduced from an information recording medium in which information composed of a plurality of codes differing in length is recorded and evaluates the reproduced signal on the basis of the reproduced signal of the next shortest code after the shortest code reproduced from the information recording medium.
摘要:
Signal quality evaluation is performed using a predetermined reproduction signal, a first pattern corresponding to a signal waveform pattern of the reproduction signal, and a given pattern corresponding to the signal waveform pattern of the reproduction signal and being different from the first pattern.
摘要:
Address information is formed by M wobbles (integer M is the number of wobble waves) per bit as a basic unit, and is NRZ-recorded. Also, a sync signal used in sync detection of the address information is formed by N wobbles per bit as a basic unit (integer N is the number of wobble waves and M=2N). The sync signal with such configuration (6 wobbles per bit) is recorded on the head side of the address information (12 wobbles per bit). In this way, even when external noise is large, a modulated wobble signal can be demodulated more accurately.
摘要:
An information storage medium according to an embodiment of this invention includes a wobbled groove having a wobble period modulated by multi-frequency shift keying corresponding to playback control information.
摘要:
An optical disk medium in which a learning area can be expanded, an optical disk information recording method and an optical disk apparatus are provided. A first lead-in area and second lead-in area are provided on the inner side and outer side of a data area. The first lead-in area includes a first learning area, management information recording area and data connection area and the second lead-in area includes a protection area which protects the user data in the inner portion thereof and a second learning area which is provided on the outer side of the protection area and sets an optimum condition for an operation of recording data into the data area. An area in which information indicating the utilization state of the protection area is recorded is prepared in one of the management information recording area and data connection area.
摘要:
An optical disc medium includes a system area and a data area following the system area. A plurality of sets of an extended record control data area, a bordered area, and a border are possibly set in the data area continuously from the system area, and a first set of the plurality of sets does not include the extended record control data area. A user data is recorded in each of the bordered areas. In each of the plurality of sets other than the first set, a record control data associated with the user data which is recorded in the bordered area of the set is recorded in the extended record control data area.
摘要:
According to one embodiment, an information recording and reproducing apparatus including, a focus control module, an objective lens control module, a calculation module, and a tracking control module. If, detection the recording marks line, to focus a laser light of a second wavelength to the recording layer through an objective lens and to operation a recording layer tracking control using a tracking error signal taken out from a second reflected light and a laser light of a first wavelength to a track groove through the objective lens and to operation a guide layer tracking control to control the objective lens using a tracking error signal taken out from a first reflected light.
摘要:
According to one embodiment, a data storage device includes a data recording medium, a light source, and following units. The light application unit splits the laser beam from the light source, and applies the first and second light beams to the data recording medium from different directions. The light detection unit detects reflected light beams from the data recording medium. The light deflection unit deflects the reflected light beams to direct the reflected light beams to the light detection unit. The arithmetic unit calculates positional error information based on the detection signal. The drive unit displaces a position and a posture of the data recording medium based on the positional error information.
摘要:
According to one embodiment, a pickup head includes a plurality of light sources, a first objective lens, second objective lens, a driving unit, a first control unit, a second control unit, light receiving units. The first objective lens focuses a first light beam at a first recording layer. The second objective lens focuses a second light beam at a second recording layer. The driving unit moves the first objective lens and the second objective lens in a first direction and a second direction. The first control unit corrects displacement from target track along the first direction. The second control unit controls a moving direction of a position of the second light spot in the second direction.