Data slice generation method and apparatus for optical disk drive

A data slice signal generation method for an optical disk drive, each of optical disks used in the optical disk drive including header areas and data areas made of different materials, the method comprising the steps of:

• generating a data slice signal based on a radio frequency signal read by an optical pickup head of the optical disk drive, wherein the radio frequency signal comprises multiple waves;
• recording data slice values of the data slice signal in the end of the header area and the data area;
• adjusting the data slice signal to take the recorded data slice value in the end of the header area when the optical pickup head enters the next header area, and to take the recorded data slice value in the end of the data area when the optical pickup head enters the next data area;
• and
• adjusting the data slice signal to approach to central levels of the multiple waves of the radio frequency signal by one wave after another.

A data slice signal generation apparatus for an optical disk drive, optical disks used in the optical disk drive including header areas and data areas made of different materials, the apparatus comprising:

• a data slice generation circuit which receives a radio frequency signal read by an optical pickup head of the optical disk drive to generate a data slice signal;
• an area changing signal generation circuit for generating an area changing signal so as to indicate whether the optical pickup head switches between the header areas and the data areas;
• an area level selection circuit for selecting the data slice values of the data slice signal in the header areas or in the data areas;
• a switch logic circuit which selects the data slice signal or the data slice values as the output based on the area changing signal;
• and
• a comparator which receives the radio frequency signal and the output of the switch logic circuit to conduct an analog-to-digital conversion.