Apparatus for reproducing a digital signal

Claim 1

A digital signal reproducing apparatus for a recording medium on which a plurality of signal blocks are recorded on a plurality of recording tracks and reproduced using a rotary head, said rotary head being rotated at a speed at least twice the normal speed, characterised in that it comprises: error detection means for performing error detection of a reproduced signal for each signal block; memory means for storing a detection signal from said error detection means and the reproduced signal from the . signal block corresponding to the detection signal; and means for checking the content of said detection signal in said memory means and, when the detection signal represents no error, preventing the reproduced signal of a signal block corresponding to the detection signal from being again written with said memory means.

Claim 4

An apparatus according to claims 1 or 2, for use with a recorded signal including first signal blocks recorded with a track address signal and a block address signal at predetermined positions, and second signal blocks recorded with a block address signal at a predetermined position, said blocks being alternately arranged on the recording track of said recording medium, and wherein said apparatus further comprises: a memory for storing the reproduced signal; error check means for checking an error of each signal block; detection means for detecting that the reproduced signal is generated from said first signal block; window signal generating means responsive to said detection means for outputting a window signal corresponding to the time during which the second signal block following immediately after the first signal block on the recording tract is reproduced; timing signal generating means for generating a timing signal when said window signal is generated and said error check means generates a signal indicating that no error is detected; and address signal generating means for generating an address signal for causing the reproduced signal from the second signal block to be stored in said memory means based on the block address signal of the second signal block and the trace address signal of the first signal block when said timing signal is detected.

Claim 6

An apparatus according to any one of the preceding claims, further comprising: extraction means for extracting a track address signal and a block address signal included in the reproduced signal obtained from said rotary head; pulse signal generating means for generating a pulse signal having a predetermined time interval at a predetermined timing based on the block address signal; detection means for detecting the track address signal included in the predetermined time interval from the track address signal based on the pulse signal; comparison means for comparing the detected track address signal and a reference track address signal; and control means for controlling travel of said recording medium in accordance with said comparison means.