Objective lens driving device
AssigneeSanyo Electric Co., Ltd.
InventorChikashi Yoshinaga
Life of this patent
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Abstract
The height of a tracking coil in an objective lens driving device having a cover over a magnetic circuit is freed from limitations imposed by the cover, so that an effective length of the tracking coil can be ensured. Magnets 2, 3 generating an effective flux and facing yokes 6, 7 facing the magnets are provided such that effective edges of a focusing coil 12 and a tracking coil 13 are located in an air gap. A cover 19 is provided over the top surface of the magnets 2, 3 and the facing yokes 6, 7. The cover 19 has a notch formed for exposing the tracking coil 13 so as to avoid limiting the height of the tracking coil 13, thereby securing an appropriate effective length of the tracking coil 13 within the effective flux.
Claims3
An objective lens driving device comprising a cover over a top surface thereof and movably supporting a lens holder having an objective lens mounted thereon with respect to a frame by an elastic supporting member, wherein the lens holder includes a focusing coil and a tracking coil attached thereto, the objective lens driving device includes a magnet generating an effective flux and a facing yoke provided such that effective edges of the focusing coil and the tracking coil are located in an air gap, and the cover is provided over a top surface of the magnet and a top surface of the facing yoke and includes an opening for exposing the tracking coil.
Dependencies are inferred from the claim text.