Pioneer Electronic Corporation

Shinichi Okada

Naoharu Yanagawa

Kyota Funamoto

Kanji Ishihara

Keiji Katata

An information reading apparatus has a feature that, when a disc on which data is recorded by a CLV system is read out by a CAV system, a transfer rate is changed in accordance with an amount of data recorded on the disc and the data can be efficiently read out in a short time. In an information reading apparatus arranged such that data read by rotating at a constant angular velocity a disk-shaped recording medium on which data is recorded at a constant linear velocity is transmitted to an external apparatus through a buffer memory, there is provided a setting unit for setting a rotational angular velocity of the disk-shaped recording medium in a manner such that a transfer rate when the information read at a predetermined radial position excluding the outermost peripheral portion in the information recording region of the disk-shaped recording medium is transferred to the buffer memory is equal to the maximum sustain transfer rate at which the information reading apparatus can perform the reading operation.

Information reading apparatus

A method of recording an optical disk, by irradiating a laser light onto a predetermined track of the optical disc to record information pits corresponding to an input composite signal including data signal and synchronization signal, includes the steps of: detecting a record timing of the synchronization signal to be recorded; and reducing at least one of a recording power and a recording duty of the laser light when the information pit corresponding to the synchronization signal is recorded by the laser light, according to the detected record timing.

Reducing the recording power based on the timing of recorded

Disclosed is an information recording/reproducing apparatus using an optical recording medium, which can reproduce information from a recording medium designed to have a high linear recording density, by a method of performing signal separation/extraction by one threshold level in a level detecting process at the time of information reproduction from an optical recording medium with a high linear recording density. The information recording apparatus comprises a data converting means for perform data conversion on record information consisting of a digital signal in accordance with a predetermined data conversion table including a pattern for yielding a converted pattern consisting of at least one '0' and an even number of consecutive '1' or a converted pattern having a section consisting of '01010' and a section consisting of at least one '0' or an even number of consecutive '1'; a data modulating means for inverting an initial output signal when bit information of data after the data conversion is '1' given that the initial output signal is '0'; and a recording means for recording the output signal on an optical recording medium. The information reproducing apparatus comprises a reading means for reading information from the optical recording medium to yield a reproduced signal; a level detecting means for detecting a level of the reproduced signal and outputting digital data; an error correcting means for, upon detection of a sequence of '01110' in a bit pattern of the digital data, correcting the sequence to a sequence of '01010' and outputting corrected data, and, upon detection of no error, outputting the digital data; and a data reverse converting means for performing reverse conversion on the output data of the error correcting means in accordance with the data conversion table, yielding reproduced information.

Information recording reproducing apparatus using data conversion to

An apparatus for reproducing data from a recording medium on which data including phase adjustment pattern data are recorded, the phase adjustment pattern data including a plurality of solitary waves, the apparatus including: unit for reproducing the recorded data from the recording medium in synchronism with a read clock and producing a reproduced signal; unit for extracting the phase adjustment pattern data from the reproduced signal and producing the solitary wave signal; unit for detecting a phase shift between the reproduced signal and the read clock on the basis of the solitary wave signal; and unit for adjusting phases of the read clock and the reproduced signal to be in phase with each other on the basis of detected phase shift.

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Tokorozawa, Japan

Shinichi Okada