Patent ID: 7012869

Claim:
A reproduction apparatus that reproduces an optical disc, comprising: a signal reproduction means for generating an RF signal by reading a pit string on the optical disc using laser light; a first binary signal generating means for converting the RF signal into a first binary signal using a first threshold value, the first binary signal including a plurality of high sections and a plurality of low sections, each high section corresponding to a convex part having a length within a range from a first length to a second length or a certification convex part having a length less than the first length; a second binary signal generating means for converting the RF signal into a second binary signal using a second threshold value, the second binary signal including a plurality of high sections and a plurality of low sections, each high section corresponding to a convex part having a length within the range from the first length to the second length; an EX-OR calculation means for calculating an exclusive OR of the first binary signal and the second binary signal; and a judging means for judging, according to the calculated exclusive OR, whether certification convex parts exist on the optical disc with a predetermined distance therebetween.