Patent ID: 6240059
Filing Date: 2001-05-29
Classification: G11B

Abstract:
An off-axis optical pickup mechanism for an optical storage drive, said mechanism particularly adapted for accessing data tracks of a dual-sided optical storage disc, said dual-sided disc having a first side and second side, both said first side and second side having readable data tracks, said mechanism comprising:an optical pickup unit, said optical pickup unit emanating a light beam through an eye, said eye also receiving a reflected light beam which is reflected back from said optical storage disc;an optical pipe having a top, bottom, and a main channel for directing the light beam emanating from said optical pickup unit and the reflected light beam,said top and bottom channels having a lens element at one end, said top and bottom channels connected to said main channel at another end, said lens element of said top channel positioned over said first side of the disc, and said lens element of said bottom channel positioned over said second side of the disc,said main channel having an opening at an end, and a semi-transparent reflecting means for directing a part of the light beam emanating from said optical pickup unit to said bottom channel and allowing a part to pass through to said top channel, said semi-transparent reflecting means also directing the reflected light beam in the bottom channel to said opening of said main channel and allowing the reflected light beam in the top channel to pass through to said opening of said main channel,reflecting means in the top channel for directing the light beam emanating from said optical pickup unit towards said lens element of said top channel and for directing said reflected light beam to said opening of said main channel, reflecting means in the bottom channel for directing the light beam emanating from said optical pickup unit towards said lens element of said bottom channel and for directing said reflected light beam to said opening of said main channel,said optical pipe rotatably positioned over said optical pickup unit with said opening in the main channel positioned directly over said eye such that said opening can receive the light beam emanating from said optical pickup unit and direct the reflected light beam back into said eye of the optical pickup unit; anda mechanism for controllably rotating and positioning said optical pipe such that said lens elements can be placed in position to access said data tracks of said first and second side of the optical storage disc without having to move said optical pickup unit.