Patent ID: 6331969
Filing Date: 2001-12-18
Classification: G11B

Abstract:
An optical disk recording apparatus for forming a first modulating signal whose signal level switches at each of a plurality of time periods in accordance with a main data row representing a first data, each of said time periods being an integer multiple of a predetermined basic period of time, wherein an optical beam that is controlled in accordance with the first modulating signal is transmitted onto a disk-like record medium to successively form pits and lands in accordance with each of said periods, said apparatus comprising:first modulating signal forming means for forming the first modulating signal in accordance with the main data row;pulse width detecting means for detecting a pulse width of the first modulating signal and outputting a result of the detection of the pulse width;modulating signal processing means for forming a double modulating signal by modulating the signal level of the first modulating signal at said predetermined time period in accordance with a subcode and the detection of the pulse width;means for determining whether a pit is of a predetermined length or longer;means for determining a predetermined distance from an edge of the pit corresponding to a predetermined time period;record beam modulating means for modulating the optical beam in accordance with the double modulating signal; andmeans for changing a width of the pit at said predetermined distance based on the subcode representing a second data; andan optical system for transmitting the optical beam onto the record medium.