Sony Corporation

Yuji Arataki

Yasuaki Maeda

Kenichi Kabasawa

Shozo Masuda

Han Min-Jae

Hiroshi Yamaguchi

Hirokazu Imazeki

Tohru Kadono

Osamu Nagata

Tadao Yoshida

Hiraku Inoue

Tetsuji Nakazawa

A recording medium on which a plurality of programs are collected in a plurality of groups and supervised in this grouped state, wherein when an editing command such as dividing, linking, and erasing the predetermined programs or groups recorded on the recording medium is executed, management data is edited to perform the editing command. The invention provides a solution to meet this request by a recording medium, an editing method and an editing apparatus.

Recording medium, editing method and editing apparatus

When a data is recorded to a recording medium, a miserasing preventing circuit determines whether or not a track jump is caused by a shock or a scratch. If it is caused by a shock, such as a quantity of light of an optical pick-up is controlled to change a reproducing state, and then the optical pick-up is moved to the rerecording position to start rerecording. As a result, recorded area is not disturbed, and the rerecording control is not performed by a little dust. Thereby, it can be provided an apparatus with high recording efficiency.

Data erasure preventing method and circuit thereof and optical disc apparatus mounting the same

In a recording method for a recording medium having a data recording area on which a data recording and/or reproducing operation is carried out, and a management data area on which management data to manage a recording and/or reproducing operation for the recording medium are recorded, when new data are recorded on the recording medium in a state where data have been already recorded on the recording medium and a data-recordable area on which the new data can be recorded exists on the data recording area, the recording operation of the new data is started from the head position of the data-recordable area on the basis of the management data recorded on the management data area, and data which have been already recorded on the recording medium are deleted by the same data amount as the new data to be recorded on the data-recordable area from a position on the data recording area of the recording medium at which the recording operation is instructed to start.

Methods and apparatus for recording data on and deleting already

The present invention provides a method for recording digital data utilizing a digital recording system having a recording area. The method includes a recording step and an erasing step. The recording step includes recording a first digital sequence in the recording area. The first digital sequence is then both preceded by and followed by a non-recordable area. The erasing step includes erasing the first digital sequence, as well as both non-recordable areas from the recording area, pursuant to a command to erase the first digital sequence. A start address and an end address is kept in a management area of the recording medium for each digital sequence stored in the recording area. When a command to erase the first digital sequence is received, a magnetic head and an optical pick-up sequentially erase from an address following an end address of a preceding sequence to an address preceding a start address of a succeeding sequence. Information on start and end addresses of digital sequences and their positions with respect to each other both physically on the disk and as they are read pursuant to a read command is stored in tabular form in the management area. An apparatus for performing the above operations is also provided.

Apparatus and methods for minimizing non-recordable areas and numbers of

A recording/reproducing apparatus is free from a jitter problem caused by a rotational drive of a recording medium such as a magneto-optical disk. A reproducing apparatus is comprised of: reproducing means for reading out data from a recording medium; signal processing means for performing a predetermined signal process to the data read by the reproducing means; storage means for temporarily storing the data processed by the signal processing means; write control means for controlling a writing operation of the signal-processed data into the storage means; read control means for controlling a reading operation of the data temporarily stored in the storage means therefrom; first clock generating means for extracting a clock synchronized with the drive of the recording medium from the data reproduced from the recording medium to thereby generate a first clock; second clock generating means for generating a stabilized clock; and control means for controlling both of the signal processing means and the write control means based upon the first clock generated from the first clock generating means, and also for controlling the read control means based on the stabilized clock generated from the second clock generating means.

Decoder/encoder capable of controlling data reading/writing operations

Disclosed are a rotation servo circuit and a reproducing apparatus equipped therewith. In the rotation servo circuit, the average value of an inversion probability pattern of a run length code recorded on a recording medium is calculated in advance and, on the basis of the average value thus obtained, a reference rotation voltage is generated, so that a rotation in accordance with the reference rotation voltage is effected whenever a reference number of revolutions is deviated from.

Rotation control circuit based on the mean value of run length code

A data reproducing apparatus reproduces a data recorded or medium which has auxiliary data added to main data subjected to an error correction coding process. The data reproducing apparatus includes a signal processor, a memory, a comparator and a controller. The signal processor separates the main data from the recording data read out from the recording medium to implement an error correction decoding process thereto. The memory means stores the decoded main data from the signal processor. The comparator compares the last data stored in the memory with the inputted main data to the memory. The controller controls write and read operations of the memory and controls the comparison condition of the comparator according to the main data from the signal processor.

Data reproducting apparatus with controlled comparator for reducing

Data reproducing apparatus with controlled comparator for reducing

A data reproducing apparatus for reproducing main data from a disc on which a data string comprised of main data and auxiliary data appended to the main data at intervals of predetermined lengths of the main data, which main data are previously error correction coded input digital data. The main data are separated from data read from the disc and error-corrected in a decoder. The error-corrected data are stored in a memory. The data stored in the memory are continuously read by a readout control circuit. Data patterns before and after connecting portions of the main data written in or read from the memory are compared in a comparator and the next data are continuously reproduced at a time point when the data pattern coincidence is detected in the comparator.

Error correction coded digital data reproducing apparatus

During recording the inputted data are sequentially written into a memory at one transfer rate and are read out at a second, higher transfer rate for recording on a record medium. The reading of the memory is such that data in a preset first amount are successively read from the memory to always ensure a write space in the memory which has a capacity which is higher than a predetermined second amount when the amount of the inputted data stored in the memory exceeds the first amount. During playback, the recorded data are reproduced at a second transfer rate, which is higher than a first transfer rate required for outputting the reproduced data, and are written in the memory. The thus written data are successively read out of the memory as reproduced output data at the first transfer rate. The writing of the reproduced data to the memory is controlled so that a second amount of the reproduced data is written into the memory and an amount of reproduced data, not less than a first amount, is always stored in the memory when the amount of the reproduced data stored in the memory becomes not higher than the first given amount.

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Tokyo, Japan

Yuji Arataki