摘要:
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.
摘要:
A recording medium having a dummy signal area on at least one side of a recording area is used and information is recorded with a dummy signal added to at least one of the leading and trailing sides in the recorded information signal. The user data area remains unaffected by repeated overwriting so that recorded user data is reproduced correctly. In particular, the wave form distortion caused by fluidization of a recording film remains at the dummy signal area and does not affect the user data area, so that the reproduction of the target information (user data) is assured.
摘要:
A recording medium has a dummy signal area on at least one side of a recording area, and information is recorded with a dummy signal added to at least one of the leading and trailing sides in the recorded information signal. The user data area remains unaffected by repeated overwriting so that recorded user data is reproduced correctly. In particular, the wave form distortion caused by fluidization of a recording film remains at the dummy signal area and does not affect the user data area, so that the reproduction of the target information (user data) is assured. The recording medium further stores thereon information concerning the pattern of the dummy signal that is used, for example the duty cycle of the dummy signal. The information may be recorded in the control data area of the recording medium.
摘要:
An optical information processing apparatus includes an optical recording medium having an information recording area constituted by groove portions and land portions alternately arranged in a radius direction, a prepit portion constituted of the groove portions intermittently arranged with alignment in the radius direction, and prepits used for address information meanderingly arranged with respect to center lines of the groove and land portions in a circumferential direction on the information recording area and the prepit portion; a motor which rotates the optical recording medium; a light irradiator which irradiates an optical spot on the optical recording medium; and an optical detector which detects a reflected light from the optical recording medium to obtain a reproduced signal. The light irradiator irradiates the optical spot having a predetermined spot diameter to enable detection of the prepits meandered through the center line among the meanderingly arranged prepits through center lines of the groove and land portions in a circumferential direction by the optical detector when irradiating the optical spot on the prepit portion.
摘要:
An information recording method for recording information by forming record marks in a data region of a recording medium such that the information corresponds to both ends of each of the record marks. First and second adjustment or guard regions are provided before and after the data region. The lengths of the first and second adjustment regions are changed with the start position of the first adjustment region being changed such that the position of the data region is shifted. In addition, when the same information is recorded a plurality of times, an array of record marks recorded on the recording medium in association with the information includes an array in which the record marks and the spaces between the marks are reversed each other in their positions.
摘要:
Provided is a microtome in which refrigerant piping and electrical wiring are not impeditive so that cleaning and other works can be surely conducted.The microtome includes a head 32 which holds a sample, an alignment mechanism 50 which aligns a head 32, a body portion 42 which is provided on the back face side of the alignment mechanism 50, a cylindrical coupling portion 41 which couples the body portion 42 with the head 32, a temperature controller 34 in the head 32, and refrigerant piping 40 and electrical wiring 46 for the temperature controller 34, and the alignment mechanism 50 includes a spherical member 68 coupled with the back face side of the head and having a spherical outer periphery and includes retainer portions 70 and 71 retaining the outer periphery of the spherical member 68 slidably along a spherical surface, the spherical member 68 has a through hole 74 formed communicating with the hollow portion 43 of the coupling portion 41, and the refrigerant piping 40 and the electrical wiring 46 are connected with the temperature controller 34 in the head 32 through the through hole 74 of the spherical member 68 and the hollow portion 43 of the coupling portion 41.
摘要:
Since the conventional optical disk recording/reproducing apparatus cannot correctly measure a power of a main beam that is a part of the laser light outputted from an objective lens and is focused on a recording layer to contribute to recording/reproducing, it is difficult to accurately control a read power. A ratio of a proper read power to a threshold power of erasing is acquired beforehand. The read power is determined by measuring the threshold power of erasing and multiplying it by the ratio when learning of the read power is performed for each drive device. According to the read power learning method of this invention, it becomes possible to determine the proper read power regardless of performance variance of an optical pickup and sensitivity dispersion of a medium.
摘要:
A highly efficient and reliable reproduced signal evaluation method and an optical disc drive using that method in which assuming that the number of 2T's appearing successively in a predetermined evaluation bitstream is i, the evaluation bitstream is divided into a main bitstream (5+2i) long and sub bitstreams at the ends of the main bitstream. The check process to determine whether a predetermined evaluation bitstream is included in the binarized bitstreams is replaced with a main bitstream agreement check. This can prevent an increase in the circuit size. At the same time, by separately summing up for each main bitstream the calculated results of Euclidean distance between the reproduced signal and the target signal corresponding to the evaluation bitstream, the size of an evaluation summing circuit can be reduced.
摘要:
An optical disc using super-resolution effects that achieves higher-density recording exceeding the optical resolution suffers from the signal-quality degradation caused by the normal resolution component included in the reproduction signal. To address this problem, a data reproduction method is provided. In the method, characteristic error patterns are identified and parity check codes in conformity with run-length limited coding are used to carry out efficient and reliable error correction. Error patterns caused by the normal resolution crosstalk are localized in the leading edges of a mark following a long space and in the trailing edges of a long mark. Whether an error exists in the data is determined by use of the parity check codes. When an error occurs, a pattern in which an error is most likely to occur is selected from the above-mentioned patterns by taking account of the edge shift direction, and then the error therein is corrected.
摘要:
A highly efficient and reliable reproduced signal evaluation method and an optical disc drive using that method in which assuming that the number of 2T's appearing successively in a predetermined evaluation bitstream is i, the evaluation bitstream is divided into a main bitstream (5+2i) long and sub bitstreams at the ends of the main bitstream. The check process to determine whether a predetermined evaluation bitstream is included in the binarized bitstreams is replaced with a main bitstream agreement check. This can prevent an increase in the circuit size. At the same time, by separately summing up for each main bitstream the calculated results of Euclidean distance between the reproduced signal and the target signal corresponding to the evaluation bitstream, the size of an evaluation summing circuit can be reduced.