Information recording and reproducing method and system for disc-shaped recording mediums

A method of controlling the rate of change of a read/write clock frequency in a MCAV optical disc system having a read/write head recording and reading information on a recording medium in response to a read/write clock frequency, comprising the steps of:

• forming a plurality of spiral recording tracks on said medium, each of said tracks being further provided with a plurality of information sectors, each of said sectors being provided with an information header having a clock pattern to accommodate synchronization with said read/write clock frequency;
• creating a plurality of circumferential zones, each of said zones comprising a plurality of said tracks, wherein at least pairs of said tracks have a same track address, each of said zones having one more of said sectors than an adjacent radially inner one of said zones, and one less of said sectors than an adjacent radially outer one of said zones;
• and
• changing said read/write clock frequency as a function of the number of said sectors in said zones which are traversed by said read/write head during a reading or recording of information on said recording medium.

An optical disk system having a read/write head for recording and reading information in response to a read/write clock, which comprises:

• a) a disk recording medium having a plurality of spiral recording tracks, with each of said recording tracks having a plurality of information sectors and each of said sectors having an information header with a clock pattern for accommodating synchronization with said read/write clock, said disk recording medium further having a plurality of logical tracks, each of which includes at least one of said recording tracks, and a plurality of circumferential zones with each of said zones having at least one of said logical tracks and one more of said sectors than an adjacent radially inner zone, and one less of said sectors than an adjacent radially outer zone;
• b) position control means mechanically connected to said read/write head for locating said read/write head at one of said sectors of said disk recording medium in response to position information signals;
• c) command control means in electrical communication with said position control means for generating said position information signals, recording data signals, pulse width control signals, and clock control signals;
• d) recording control means in electrical communication with said command control means and said read/write head, and responsive to said recording data signals, said pulse width control signals and said clock control signals for recording information on said disk recording medium;
• e) read control means in electrical communication with said disk recording medium and said command control means for receiving recorded information signals from said read/write head and producing a pulsed data signal for storage in said command control means.