Optical pickup is an optical apparatus to record and/or reproduce information from an optical disc. It is a kind of large aperture optical system of diffraction limited. As a product of mass production, its accuracy is guaranteed by reasonable balance among fabricating and assembling tolerances of optical, mechanical and optoelectronic elements. One method employed is conduct sensitivity analyses to identify tolerances for each element, which usually limits the manufacturability and cost of optical pickup. In this paper, the method of optical pickup virtual analyzer is proposed to improve the manufacturability. The mathematical modeling used for virtual analyzer is established based on the system image quality and laser spot characteristics on photo detector. First, a three-dimensional virtual optical pickup model is established, in which the characteristics and fabricating and assembling errors of each optical element (beam splitter, mirror, collimator and objective ), optoelectronic element (laser diode and photo diode)and mechanical support element are described. The optical disk is represented as a reflective surface. The photo diode integrated circuit could work virtually so that it could receive the laser spot reflected from the optical disk. The photosensitive division on it would differentiate the laser spot on it and give the signals according to requirements of the real analyzer. The virtual analyzer can help combine suitable elements of looser tolerance for optical pickup assembling and improve the manufacturability efficiently. The mathematical model is developed using the Macro-PLUS language and a CD/DVD optical pickup virtual analyzer is successfully optimized with the model.

Date Published: 28 November 2007
PDF: 9 pages
Proc. SPIE 6834, Optical Design and Testing III, 68340N (28 November 2007); doi: 10.1117/12.757844

Published in SPIE Proceedings Vol. 6834:
Optical Design and Testing III
Yongtian Wang; Theo T. Tschudi; Jannick P. Rolland; Kimio Tatsuno, Editor(s)