Digital data reproducing apparatus and method employing buffer memories for error compensation and accomodating differences in reproduction and processing rates

A digital data reproducing apparatus for reproducing digital data in coded form from a disk, comprising:

• pickup means for picking up the digital data from the disk;
• sector detecting means for detecting a sector number from the digital data picked up by the pickup means and producing an error occurrence signal in response to a failure to regularly detect the sector number;
• first storage means for storing the digital data and for reading the stored digital data therefrom at a variable rate;
• second storage means for storing the digital data read from the first storage means, the second storage means being operative to store the digital data at said variable rate and to read the digital data stored therein;
• decoding means for decoding the digital data read by said second storage means;
• and
• jump controlling means for causing said pickup means to track jump in accordance with the error occurrence signal and an amount of data stored in said first storage means.

A digital data reproducing apparatus for reproducing digital data in coded form from a disk, comprising:

• pickup means for picking up the digital data from the disk;
• error detecting means for detecting an error in the digital data picked up by said pickup means and producing an error occurrence signal;
• first storage means for storing the digital data therein and for reading the stored digital data therefrom at a variable rate, said first storage means having a storage capacity greater than twice an amount of data in a track proximal to an outermost circumference of the disk;
• second storage means for storing the digital data read from the first storage means, the second storage means being operative to store said digital data at said variable rate and to read the stored digital data therefrom;
• decoding means for decoding digital data read from said second storage means;
• and
• jump controlling means for causing said pickup means to track jump in accordance with the error occurrence signal.

A digital data reproducing method for reproducing digital data recorded on a disk, comprising the steps of:

• picking up the digital data from the disk;
• writing the digital data in a first memory at a first transfer rate within a first predetermined range;
• reading the digital data stored in said first memory at a second transfer rate which is below the first predetermined range and which is variable;
• storing the digital data read from said first memory in a second memory at said second transfer rate;
• and
• reading the digital data stored in said second memory at a variable rate within a second predetermined range including at least one value higher than a maximum value of the first predetermined range.