Please refer to
Please refer to
The magnetic field producing apparatus is used to produce a first magnetic field and a second magnetic field. The magnetic direction of the first magnetic field is perpendicular to the surface of the optical disk 10; the magnetic direction of the second magnetic field is parallel to the surface of the optical disk 10. The magnetic field producing apparatus includes two magnetic elements such as the first magnet 422 and the second magnet 424; the first magnet 422 is horizontally placed above the lens holder 410 while the second magnet 424, corresponding to the first magnet 422, is placed horizontally below lens holder 410.
Coiling device 430 is horizontally placed and affixed on the lens holder 410, and it is constructed by fine pattern coils on a plastic substrate or a print circuit coils on a print circuit board; thus the coiling device 430 is a planar coiling device 430 with very thin thickness. On the coiling device 430 focusing coils 432a, 432b and tracking coils 434a, 434b can be formed; focusing coils 432a, 432b and tracking coils 434a, 434b can be coiled into a rectangular or a circular shape. When a first current is conducted through tracking coils 434a, 434b, a first force created by the first current interacting with the first magnetic field will move the lens holder 410 which in turn leads actuator 400 to move along the tracking direction. When a second current is conducted through focusing coils 432a, 432b, a second force created by the second current interacting with the second magnetic field will move the lens holder 410 which in turn leads actuator 400 to move along the focusing direction; tracking coils 434a, 434b and focusing coils 432a, 432b will be placed on the same horizon as illustrated in
Further, two fixing parts 442 can be placed respectively on two sides of lens holder 410; through these two fixing parts, metallic wires 440a, 440b, 440c, 440d can go through to keep lens holder 410 at a hanging status. Since metallic wires 440a, 440b, 440c, 440d must provide for current to be conducted in and out of the focusing coils 432a, 432b and the tracking coils 440c, 440d, the top and bottom planes of coiling device 430 can each form two bonding pads respectively for a total of four bonding pads 446a, 446b, 446c, 446d, to be connected to fixing part 442, respectively by the metallic wires 440a, 440b, 440c, 440d. As illustrated in the present invention, coiling device 430 comprises of two focusing coils 432a, 432b, and two tracking coils 434a, 434b. The first current can run through metallic wire 440a, bonding pad 446a, into first tracking coil 434a, and out of first tracking coil 434a, into second tracking coil 434b, out of second coil 434b to then run through bonding pad 446b and metallic wire 440b and finally out of actuator 100. By the same logic, the second current can run through metallic wire 440c, bonding pad 446c, into first focusing coil 432a, then out of first focusing coil 432a to run into second focusing coil 432b; after second current runs out of second focusing coil 432b it can then run through bonding pad 446d and metallic wire 440d and finally out of actuator 100. As shown in
In order for lens holder 410 carrying lens 412 to move along focusing or tracking directions after currents are respectively conducted through focusing coils 432a, 432b and tracking coils 434a, 434b, the horizontal arrangement of the first and second magnets 422, 424 above and below lens holder 410 will be devised to have a plurality of magnetic areas having different polarities in response to the corresponding positions of the focusing coils 432a, 432b and tracking coils 434a, 434b.
Please refer to
A first polarity, such as S, is assigned to the magnetic areas neighboring to coiling device 430, of first magnetic area 422(1), third magnetic area 422(3), and fifth magnetic area 422(5) of first magnet 422 and first magnetic area 424(1) and fifth magnetic area 424(5) of second magnet 424. A second polarity, for instance N, is then assigned to the other magnetic areas neighboring to coiling device 430 including: second magnetic area 422(2) and forth magnetic area 422(4) of the first magnet 422, and second magnetic area 424(2), third magnetic area 424(3) and forth magnetic area 424 (4) of the second magnet.
By assigning, magnetic areas neighboring to coiling device 430, polarity of S on the third magnetic area 422(3) of first magnet 422 and polarity of N on the third magnetic area 424(3) of second magnet 424, the magnets can create a first magnetic field B1; the direction of such magnetic field B1 is perpendicular to the plane of coiling device 430 and the surface of the optical disk.
If first current I1 is conducted through tracking coils 434a, 434b, the first magnetic field will interact with first magnetic field B1 to form a first force F1. Since hanging apparatus 440 is keeping lens holder 410 at a hanging status, such first force F1 can enable lens holder 410 to move along the tracking direction.
Please refer to
When second current 12 is conducted through focusing coils 434a, 434b, under the influence of second magnetic field B2, actuator 400 will produce a second force F2 according to second current 12; second force F2 then prompts the lens holder 410 to move along focusing direction.
The perpendicular first and second forces will prompt lens holder to move along tracking or focusing direction in order to read or write information. The design of lens holder is not limited to the description of presently illustrated embodiment. The same effect can still be reached with an altered design of lens holder.
The present invention is intended to cover various modifications and similar arrangements included to within the spirit and scope of the appended claims, which are to be accorded with the broadest interpretation so as to encompass all such modifications and similar structures.
Number | Date | Country | Kind |
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095123407 | Jun 2006 | TW | national |