Pioneer Corporation

Pioneer Electronic Corporation

Pioneer Electronics Corporation

Toshio Goto

Hideki Hayashi

Takashi Yamaji

An optical recording medium that enables a recording or reproduction apparatus to perform accurate tracking servo control even if intersymbol interference occurs. An optical recording medium includes a plurality of frames continuously extending in an information reading direction. Each frame is defined by a servo region for recording tracking pits used in tracking servo control and a data region for recording information data. A position of each of the respective tracking pits in each respective servo region is changed in the information reading direction between successive frames.

Optical recording medium

An information recording and reproducing method is provided with an information recording method of optically recording digital data onto an information recording medium such as an optical disc etc., by forming a pit having a shape corresponding to the digital data, and an information reproducing method of optically reproducing the recorded digital data from the information recording medium. The information recording method is provided with: a record code generating process of applying an encoding process using a convolutional code onto the digital data, to thereby convert the digital data into a record code; a multi-level symbol generating process of converting the generated record code corresponding to a plurality of bits into a multi-level symbol having a plurality of values; a record symbol generating process of applying a logical converting process onto the generated multi-level symbol to thereby convert the multi-level symbol into a record symbol; and a recording process of recording the record symbol onto the information recording medium by optically forming the pit on the information recording medium while changing the shape of the pit by several steps in correspondence with a value of the generated record symbol. The information reproducing method is provided with: an irradiating process of irradiating a light beam for reproducing the digital data so that an irradiation range of the light beam on the information recording medium covers a plurality of pits.

Information recording and reproducing method, information recording and reproducing system, information recording apparatus, and information reproducing apparatus

Digital signal sequences to be recorded in predetermined unitary recording areas are transformed into blocks, a plurality of bit data carrying all digit levels to be read and determined upon reproduction are included in the resultant blocks, and sequences of the data blocks are recorded in the recording medium in the unitary recording areas. Upon reproduction, the blocks of the read signals obtained from a recording medium are recognized, a threshold value is determined for each block on the basis of the values of read signals corresponding to bit data carrying all digit levels to be read and determined, and each digit level of bit data in the read signal are read and determined on the basis of the threshold values.

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Tsurugashima, Japan

Toshio Goto