Patent ID: 6359842
Filing Date: 2002-03-19
Classification: G06K,G11B,H01Q

Abstract:
A recording disc having a reproducible data recording area, comprising:an input part which electromagnetically inputs data; at least one semiconductor memory part which memorizes the data inputted through said input part; and an output part which electromagnetically outputs the data memorized in said at least one semiconductor memory part; wherein at least one of said input part, said at least one semiconductor memory part and said output part is positioned with respect to one another so that an eccentricity in center of gravity of said disc expressed as below, due to at least each said part is reduced to at least a set level which is no greater than 1.0 gcm when the disc is considered in the entirety thereof: &LeftBracketingBar;H&RightBracketingBar;={&Sum;i=0n&it;(mi&CenterDot;ri)x}2+{&Sum;i=0n&it;(mi&CenterDot;ri)y}2where, H is the eccentricity in the center of gravity of the disc in the entirety thereof, X and Y are X axis and Y axis which are perpendicular to each other on the disc surface, respectively, and mi and ri are mass and distance from the rotation center to the position of the center of gravity of a respective part of No. i, represented by the input part, the semiconductor memory part, and the output part, and (miÂ·ri)x and (miÂ·ri)y are X axis component and Y axis component of the eccentricity.