Patent ID: 6901042

Claim:
An optical disc comprising: a data area in which a data pit string corresponding to recorded digital data is formed, the data pit string including concave parts, convex parts, and a certification pit, the certification pit certifying that the recorded digital data is original, wherein a length of each of the concave parts and the convex parts satisfies a predetermined rule, a length of the certification pit does not satisfy the predetermined rule, the predetermined rule is based on a run length limitation method that encodes the digital data so that a zero bit sequence is obtained, a total number of zero bits in the zero bit sequence being within a range from a first number to a second number, the length of each of the concave parts and the convex parts is within a range from a first length to a second length, the first length and the second length respectively corresponding to the first number and the second number, and the certification pits is a concave part, the length of the concave part exceeding the second length.