Patent ID: 7523473

Claim:
A disc shaped optical record carrier, comprising: a disc shaped optical record carrier body having a thickness of greater than 1.4 mm and having a center hole integrally formed therethrough with a predetermined radius R 1 centrally around a rotational axis of the disc, said center hole extending from a first side to a second side; said center hole defining first and second inner edges on said first and second sides of said disc shaped optical record carrier, and a portion of said optical record carrier body adjacent to said center hole having a first clamping area and a second clamping area extending radially along said first and second inner edges, respectively, wherein said first and second clamping areas are recessed and the recesses have substantially equal depth on said first and second sides, the recesses extending along said first and second inner edges and having a first diameter, a portion of said first clamping area and a portion of said second clamping area is further recessed and the further recesses have substantially equal depth on said first and second sides, the further recesses extending along said first and second inner edges and having a second diameter smaller than the first diameter of said first and second clamping areas, and the further recesses are configured to directly receive a ball clamp.