Patent ID: 6384996
Filing Date: 2002-05-07
Classification: G11B

Abstract:
Digital signal recording apparatus comprising:a recorder, for recording parallel tracks of digital signal modulation on a recording medium; an input port for serially receiving n-bit information words; circuitry for inserting a â€œ0â€  bit into each said received n-bit information word and generating a (n+1)-parallel-bit â€œpositiveâ€  information word at an information word rate slower by a factor of (n+1) than the rate of a system clock; circuitry for inserting a â€œ1â€  bit into each said received n-bit information word and generating a (n+1)-parallel-bit â€œnegativeâ€  information word at said information word rate, which (n+1)-parallel-bit â€œnegativeâ€  information word is supplied concurrently with said (n+1)-parallel-bit â€œpositiveâ€  information word generated from the same one of said n-bit information words; a first precoder for coding each (n+1)-parallel-bit â€œpositiveâ€  information word to convert it into a corresponding â€œpositiveâ€ -information (n+1)-parallel-bit channel word, generated at a channel word rate slower by a factor of (n+1) than the rate of said system clock; a second precoder for coding each (n+1)-parallel-bit â€œnegativeâ€  information word to convert it into a corresponding â€œnegativeâ€ -information (n+1)-parallel-bit channel word, generated at said channel word rate; means for selecting one of each concurrent pair of â€œpositiveâ€ -information and â€œnegativeâ€ -information (n+1)-parallel-bit channel words for serial recording at said system clock rate, said means for selecting one of each concurrent pair of (n+1)-parallel-bit channel words for recording including first parallel-to-serial conversion means for generating first parallel-to-serial conversion results by converting the selected (n+1)-parallel-bit channel word to serial-bit form, and a selector switch responsive to a control signal for selecting one of said first parallel-to-serial conversion results for application to said recorder, for serial recording at said system clock rate; second parallel-to-serial conversion means for generating second parallel-to-serial conversion results by converting at least one of each concurrent pair of (n+1)-parallel-bit channel words to serial-bit form; and a control signal generator for selecting a prescribed spectral response for the one of the parallel tracks on said magnetic recording medium being currently recorded, for determining from said second parallel-to-serial conversion results how much respective spectral responses for â€œpositiveâ€ -information and â€œnegativeâ€ -information (n+1)-parallel-bit channel words most recently generated by said first and second precoders will deviate in energy from said prescribed spectral response if recorded in a prescribed non-return-to-zero-invert-on-ONEs format, and for comparing the amplitudes of the respective deviation results for the â€œpositiveâ€ -information and â€œnegativeâ€ -information (n+1)-parallel-bit channel words most recently generated by said first and second precoders, to generate a control signal indicating which one of said â€œpositiveâ€ -information and â€œnegativeâ€ -information (n+1)-bit channel words has a spectral response that least deviates from said prescribed spectral response.