High-frequency superimposing method and optical disk apparatus using it

Abstract

An optical disk drive includes drive current generation unit for supplying a mark forming semiconductor laser drive current and a space forming semiconductor laser drive current; first high-frequency superimposition unit for superimposing a high-frequency component on the space forming semiconductor laser drive current; and high-frequency superimposition control unit for controlling the first high-frequency superimposition unit to stop the superimposition of the high-frequency component for a predetermined duration prior to a timing at which to switch from the space forming semiconductor laser drive current to the mark forming semiconductor laser drive current, eliminating positional variations on the disk of the mark leading and trailing edges due to the high frequency superimposition.

1 . An optical disk drive for recording information by forming marks or spaces on an optical disk, comprising:
 drive current generation means for supplying a mark forming semiconductor laser drive current and a space forming semiconductor laser drive current, the mark forming semiconductor laser drive current having a drive waveform corresponding to a mark length and having a plurality of levels of current value, the space forming semiconductor laser drive current having at least one level of current value;   first high-frequency superimposition means for superimposing a high-frequency component on the space forming semiconductor laser drive current; and   high-frequency superimposition control means for controlling the first high-frequency superimposing means to stop the superimposition of the high-frequency component for a predetermined duration prior to a timing at which to switch from the space forming semiconductor laser drive current to the mark forming semiconductor laser drive current.   
   
   
       2 - 12 . (canceled)