Patent ID: 7414929

Claim:
A method for detecting and controlling disc tilt in an optical disc mechanism comprising the steps of: (A) measuring a plurality of 2-dimensional displacements of an optical lens of said optical disc mechanism in parallel, wherein measurements of said 2-dimensional displacements are staggered over a predetermined sampling interval and each of said 2-dimensional displacements comprises a sled position value and a lens focus position value; (B) extracting an absolute value of a disc tilt angle in said optical disc mechanism based upon said plurality of 2-dimensional displacements; and (C) controlling deflection of a tilt moving coil according to said absolute value of said disc tilt angle, wherein (i) a control signal is generated in response to a predetermined reference level, a predetermined offset value and a scaled version of said disc tilt angle, (ii) said scaled version of said disc tilt angle comprises a product of a measured lens focus position value and a predetermined system gain value associated with said disc tilt, and (iii) said predetermined system gain value is determined based upon a predetermined track width value, a predetermined track count value, a sensitivity of a focus coil of said optical disc mechanism, a resistance of said focus coil, a sensitivity of a tilt coil of said optical disc mechanism, a resistance of said tilt coil, and a gain of a tilt coil driver of said optical disc mechanism.