OPTICAL PICKUP, DISK DRIVE DEVICE, AND OPTICAL ELEMENT DRIVING DEVICE

摘要

[Object] To prevent the occurrence of stuck without increasing the number of components and also to restore thread engagement of a rack with a lead screw to a normal condition.;[Solution] Provided is an optical pickup including: a light source; an objective lens; an optical element; and an optical element driving device. The optical element driving device includes a lead screw having a threaded engagement portion with a thread groove formed in the threaded engagement portion, a drive unit configured to allow the lead screw to rotate, a thrust bearing configured to support an end portion of the lead screw on a side opposite to the drive unit in an axial direction of the lead screw, and a rack having a plurality of first tooth portions provided spaced apart in the axial direction to be threadably engaged with the threaded engagement portion and a second tooth portion provided closer to the thrust bearing in the axial direction than the first tooth portion to be threadably engaged with the threaded engagement portion, the first tooth portion and the second tooth portion being positioned on opposite sides across the lead screw, the rack being moved in the axial direction with a rotation of the lead screw. The lead screw includes a non-threaded engagement portion formed at the end portion of the lead screw on the thrust bearing side, the non-threaded engagement portion having no thread groove.

主权项

1. An optical pickup comprising:
a light source configured to emit a light beam; an objective lens configured to focus the light beam emitted from the light source onto a recording surface of a disk-shaped recording medium; an optical element arranged between the light source and the objective lens, the optical element having predetermined refractive power; and an optical element driving device configured to move the optical element along an optical axis direction, wherein the optical element driving device includes a lead screw having a threaded engagement portion with a thread groove formed in the threaded engagement portion, a drive unit configured to allow the lead screw to rotate, a thrust bearing configured to support an end portion of the lead screw on a side opposite to the drive unit in an axial direction of the lead screw, and a rack having a plurality of first tooth portions provided spaced apart in the axial direction to be threadably engaged with the threaded engagement portion and a second tooth portion provided closer to the thrust bearing in the axial direction than the first tooth portion to be threadably engaged with the threaded engagement portion, the first tooth portion and the second tooth portion being positioned on opposite sides across the lead screw, the rack being moved in the axial direction with a rotation of the lead screw, wherein the lead screw includes a non-threaded engagement portion formed at the end portion of the lead screw on the thrust bearing side, the non-threaded engagement portion having no thread groove.