Digital recording apparatus especially for television signals

Claim 2

A recording apparatus for forming on a recording medium a recording of a series of digital words, each word consisting of a number of word bits and each word bit of a word having a different significance from the other bits of said word, onto a recording medium, said apparatus comprising a plurality of recording heads arranged to be in recording relationship with the recording medium simultaneously to form a corresponding plurality of recording tracks, and a recording circuit having 1. means for so distributing the word bits of each digital word among the heads that the most significant of the word bits of each digital word are each received by a different one of said heads and recorded on the medium thereby and the remainder of said word bits are divided among the heads and also recorded on the medium thereby, 2. parity generating means arranged to generate a set of parity bits from said most significant of the word bits of each digital words, and 3. means for distributing the set of parity bits among the heads for recording on the medium thereby, together with the word bits, in a distribution such that the parity bits of said set received and recorded by any one head are derived exclusively from those of said most significant bits received and recorded by the other heads.

Claim 3

parity generating means arranged to generate a set of parity bits from said most significant of the word bits of each digital words, and

Claim 4

parity generating means arranged to generate a set of parity bits from said most significant of the word bits of each digital words, and

Claim 5

Apparatus according to claim 1 in which the heads are magnetic recording heads for use with a recording medium in the form of magnetic tape.

Claim 6

Apparatus according to claim 1 having means for advancing the recording medium longitudinally and in which the recording heads are mounted by a turret which is rotatable with respect to the direction of longitudinal movement of the medium so that the relative motion of the heads relative to the medium has a transverse component and the heads are carried into and out of recording relationship with the medium by rotation of the turret and the number and positioning of said heads about the turret is greater than the number of heads in said plurality of heads, and the heads of said plurality at a particular time are heads mounted by the turret which are in recording relationship with the medium.

Claim 7

means for distributing the set of parity bits among the heads for recording on the medium thereby, together with the word bits, in a distribution such that the parity bits of said set received and recorded by any one head are derived exclusively from those of said most significant bits received and recorded by the other heads.

Claim 8

means for distributing the set of parity bits among the heads for recording on the medium thereby, together with the word bits, in a distribution such that the parity bits of said set received and recorded by any one head are derived exclusively from those of said most significant bits received and recorded by the other heads.

Claim 9

Apparatus according to claim 3 in which the number of heads mounted by the turret is such that the number of heads in recording relationship with the medium is at times equal to, and at other times greater than, greater than the number of heads in said plurality of heads.

Claim 10

Apparatus according to claim 4 in which the number of heads mounted by the turret is five.

Claim 11

A reproducing apparatus for reproducing a series of digital words, each word consisting of a number of word bits and each word bit of a word having a different significance from the other bits of said Word, from a recording medium bearing a plurality of simultaneously reproducible recordings among which are distributed recorded word bits from each digital word arranged such that the most significant of the word bits of each digital word occur each on a different one of the recordings, and the remainder of said word bits are distributed among the recordings together with said most significant bits and recorded parity bits derived according to a parity code from said most significant bits of said word, said parity bits being arranged such that the parity bits of any one recording are derived exclusively from most significant word bits other that those of the said most significant word bits of said recording, said apparatus comprising reproducing heads for reproducing said recordings simultaneously each to yield reproduced most significant word bits, reproduced word bits of said remainder, and reproduced parity bits, a parity generator for deriving further parity bits according to said parity code from the reproduced most significant word bits, fault detector means operable to detect fault conditions involving the most significant word bits and reject those most significant bits detected as involving fault conditions whilst passing the others thereof by comparison of the derived parity bits with the reproduced parity bits and output means responsive, to provide as output, the said remainder of said word bits as reproduced to said reproducing heads together with only said others of the most significant bits.

Claim 12

A reproducing apparatus for reproducing a series of digital words, each word consisting of a number of word bits and each word bit of a word having a different significance from the other bits of said Word, from a recording medium bearing a plurality of simultaneously reproducible recordings among which are distributed recorded word bits from each digital word arranged such that the most significant of the word bits of each digital word occur each on a different one of the recordings, and the remainder of said word bits are distributed among the recordings together with said most significant bits and recorded parity bits derived according to a parity code from said most significant bits of said word, said parity bits being arranged such that the parity bits of any one recording are derived exclusively from most significant word bits other that those of the said most significant word bits of said recording, said apparatus comprising reproducing heads for reproducing said recordings simultaneously each to yield reproduced most significant word bits, reproduced word bits of said remainder, and reproduced parity bits, a parity generator for deriving further parity bits according to said parity code from the reproduced most significant word bits, fault detector means operable to detect fault conditions involving the most significant word bits and reject those most significant bits detected as involving fault conditions whilst passing the others thereof by comparison of the derived parity bits with the reproduced parity bits and output means responsive, to provide as output, the said remainder of said word bits as reproduced to said reproducing heads together with only said others of the most significant bits.

Claim 13

A recording of digital words each word consisting of a number of word bits and each word bit of a word having a different significance from other bits of said word, said recording comprising a recording medium having thereon a set of separately and simultaneously readable recordings each of which contains word bits and parity bits, said word bits being so distributed among the recordings that the most significant bits of any word are contained each of a different one of the recordings and the remaining bits of said word are contained by the same recordings as said most significant bits, said parity bits being derived from said most significant bits and so distributed among the recordings that the parity bits contained on any one recording are derived exclusively from those of the most significant bits which are contained on others of said recordings.

Claim 14

A recording of digital words each word consisting of a number of word bits and each word bit of a word having a different significance from other bits of said word, said recording comprising a recording medium having thereon a set of separately and simultaneously readable recordings each of which contains word bits and parity bits, said word bits being so distributed among the recordings that the most significant bits of any word are contained each of a different one of the recordings and the remaining bits of said word are contained by the same recordings as said most significant bits, said parity bits being derived from said most significant bits and so distributed among the recordings that the parity bits contained on any one recording are derived exclusively from those of the most significant bits which are contained on others of said recordings.