Patent ID: 6831286
Filing Date: 2004-12-14
Classification: A61K,A61P,G01N,G11B

Abstract:
A method for determining a tilt angle of an optical pickup head of an optical drive, applied in a jitter inspection device comprising a jig for simulating and adjusting a tilt angle of the optical pickup head, and a jitter meter installed on the jig for inspecting jitter values of the optical pickup head at different tilt angles, comprising the steps of:measuring the optical pickup head with the jitter meter utilizing a quadratic surface equation Z=ax2+by2+cx+dy+e and using the jitter inspection device, where x is the tilt angle in radial direction, y is the tilt angle in tangential direction, Z is the jitter value, and a, b, c, d, e are unknown constants; obtaining five sets of tilt angles of (x1, y1), (x2, y2), (x3, y3), (x4, y4), and (x5, y5), for the optical pickup head by adjusting the jig five times; creating a simultaneous equation according to the five sets of tilt angles and their corresponding jitter values Z1, Z2, Z3, Z4 and Z5; solving the simultaneous equation to obtain the result of a1, b1, c1, d1 and e1 for unknown constants a, b, c, d, and e; substituting the values of a1, b1, c1, d1 and e1 in the quadratic surface equation to create a quadratic surface equation Z=a1x2+b1y2+c1x+d1y+e1; solving the quadratic surface equation to obtain a minimum jitter value and an optimum tilt angle; and producing a barcode in accordance with the minimum jitter value as a basis for adjusting the emitting angle of the optical pickup head.