JP2006031784A - Objective lens drive - Google Patents

Abstract

In a conventional objective lens driving device, since the device has been increased in size and increased in process, an objective lens driving device that can be reduced in size and thickness is provided.
A movable body having an objective lens 1, a lens holder 2 for holding the objective lens, a coil portion including a focusing coil portion 3a and a tracking coil portion 3c, the first magnet 4 and the second magnet. The magnet 5 has a base that is fixed substantially in parallel so as to sandwich the coil portion of the movable body, and the coil portion of the movable body is interposed between the first magnet 4 and the second magnet 5. The width of the first magnet 4 in the tracking direction is supported movably through the gap, and is configured to be larger than the width of the mounting portion of the first magnet 5 provided on the base, and the relative position of the first magnet 4 is It is configured to be adjustable in the tracking direction.
[Selection] Figure 1

Description

  The present invention relates to an objective lens driving device used for a recording / reproducing apparatus for optically recording and reproducing information on a disk-shaped optical recording medium.

  Information is recorded and / or reproduced optically on a disc-shaped optical recording medium (hereinafter simply referred to as an optical disc) such as a compact disc (CD), a digital versatile disc (DVD), a Blu-ray disc (BD), or a mini disc (MD). As an objective lens driving device used in the optical disk device to be performed, there is a device as shown in FIG. In recent years, there has been a strong demand for high-density tracks and high transfer rates in optical disk devices for optical disk devices. For this purpose, the accuracy with which information can be recorded and reproduced stably even when optical disks are rotated at high speeds. A high objective lens driving device is required.

  The objective lens driving device includes an objective lens for converging laser light emitted from a semiconductor laser, a coil for controlling the objective lens so that the converged spot follows a track while maintaining a constant convergence state, and It consists of a magnet. Hereinafter, an example of a conventional objective lens driving device will be described with reference to FIGS.

  4 and 5, the objective lens 100 is held by a lens holder 101 having a through hole. A movable body including a substantially pentagonal focusing coil 102 and a pair of substantially quadrangular tracking coils 103 attached to the side surface of the focusing coil 102 is formed inside the through hole of the lens holder 101. . The moving body is supported by the four wires 107a to 107d so as to be movable in the focusing direction F and the tracking direction T with respect to the base 106. At this time, the focusing coil 101 and the tracking coil 103 are movably supported so as to be sandwiched simultaneously through a gap between the magnets 104 and 105 fixed to the base 106.

  A suspension holder 108 is fixed to the base 106, and a fixed substrate 110 is fixed to the back surface of the suspension holder 108.

  The wires 107a to 107d are made of an elastic metal material such as beryllium copper or phosphor bronze, and the two terminals of the focusing coil 102 and the two terminals of the pair of tracking coils 103 connected in series are independently connected to the wire 107a. Are electrically connected to the fixed substrate 110 through .about.107d.

  In FIG. 5, magnets 104 and 105 are arranged so that different polarities face each other, and the outer dimensions in the tracking direction T are substantially the same and J.

  In the objective lens driving device configured as described above, the portion sandwiched between the magnets 104 and 105 of the focusing coil 102 or the tracking coil 103 serves as a driving force generation point, and the driving force generation point is located substantially at the center of the movable body. To do. An objective lens is disposed at a position deviated from the driving force generation point, and a rising mirror (not shown) for reflecting the light beam in the focusing direction F, magnets 104 and 105, focusing coil 102, and tracking coil 103 are used. The structure of a general objective lens driving device is to reduce the thickness by avoiding mechanical interference with the driving means.

  In general, in an optical disc apparatus using the objective lens driving apparatus as described above, if the optical axis of the objective lens is tilted with respect to the light emitted from the semiconductor laser, optical aberration occurs, resulting in a decrease in signal level or S / N. The recording characteristics deteriorate because the ratio is lowered. The tilt of the objective lens with respect to the emitted light is called tilt. In order to meet the demand for higher density recording and higher transfer rate, more accurate tilt adjustment is required, but at the same time, the objective lens control device is also downsized, especially thin, due to the need for downsizing of the optical disk device. It has become an important issue.

  However, it is difficult to perform positioning control with higher accuracy in a limited space with conventional assembly accuracy.

First, in order to solve the problem of tilt generation, in Patent Document 1, a movement adjustment mechanism is added to the magnet or the magnet mounting portion so that the magnet or the magnet mounting portion is set so as to cancel the radial tilt and the tangential tilt after the assembly. Moving and adjusting the tilt, Patent Document 2 discloses the structure.
Japanese Patent Laid-Open No. 11-273104 (page 4, FIG. 1) Japanese Patent Laid-Open No. 11-339294 (page 4, FIG. 1)

  However, when the magnet and magnet mounting part are configured to be movable using conventional technology, tilt adjustment can be performed after assembly, but it is necessary to add a movable mechanism for adjustment separately, which increases the size of the device. Inevitably increase the number of processes. Therefore, there has been a problem that it cannot meet the demands for miniaturization and thinning.

  The object of the present invention is to solve such a conventional problem, and it is possible to adjust the operating point of the driving force by the magnet and the coil without requiring the addition of a special mechanism for adjustment, thereby reducing the size. An object of the present invention is to provide an objective lens driving device that can be made thin.

  In order to solve the above-described problem, in the present invention, a movable body having an objective lens, a lens holder that holds the objective lens, a coil portion that includes a focusing coil and at least one tracking coil, A magnet, a second magnet that faces the first magnet, and a base that is fixed substantially in parallel with an interval so that the first magnet and the second magnet sandwich the coil portion of the movable body. In the objective lens driving device in which the coil portion of the movable body is movably supported through a gap between the first magnet and the second magnet, the first lens in the tracking direction The width of the magnet is configured to be larger than the width of the mounting portion for mounting the first magnet provided on the base, and the second The relative position of the first magnet with respect Gunetto is characterized in that it is adjustably configured in the tracking direction.

  According to the present invention, the movement can be easily adjusted while holding the magnet at the time of assembly. Therefore, the relative position with respect to the opposing magnet can be adjusted without adding a special mechanism when the coil and the magnet are assembled. Therefore, the objective lens driving device can be reduced in size and thickness.

  In the objective lens driving device of the present invention, the width of the first magnet in the tracking direction is configured to be larger than the width of the first magnet mounting portion provided on the base, and the first magnet with respect to the second magnet is arranged. It is characterized in that the relative position of one magnet can be adjusted in the tracking direction.

  This makes it easy to adjust the movement while holding the magnet. After the coil and magnet are assembled, the relative position with respect to the opposing magnet can be adjusted without adding a special mechanism. Can be reduced in size and thickness.

  The first magnet mounting portion has a notch or a through hole so that the first magnet can be held from the mounting portion side, and the relative position of the first magnet with respect to the second magnet. May be configured to be adjustable.

  Accordingly, even when the width of the first magnet in the tracking direction cannot be made larger than the width of the attachment portion, the relative position of the first magnet with respect to the second magnet can be easily adjusted.

  In the objective lens driving device according to claim 3, the base has a through-hole through which the external holding means can pass in order to hold at least one of the magnets by an external holding means that does not constitute the objective lens driving device. Features.

  Accordingly, the first magnet can be easily held from the base side, and the relative position of the first magnet with respect to the second magnet can be easily adjusted regardless of the arrangement on the base.

  The optical disk drive apparatus according to claim 4 employs a configuration having the objective lens driving apparatus described above.

  According to this configuration, since the above-described objective lens driving device is used, it is possible to provide an optical disk drive device that can be reduced in size and thickness by reducing materials and processes.

  The information processing apparatus according to claim 5 employs a configuration having the optical disk drive apparatus described above.

  According to this configuration, since the optical disk drive device described above is used, it is possible to provide an information processing device that can be reduced in size and thickness by reducing materials and processes.

  In the music reproducing apparatus according to the sixth aspect, the optical disk drive apparatus described above is included.

  According to this configuration, since the optical disk drive device described above is used, it is possible to provide a music playback device that can be reduced in size and thickness by reducing materials and processes.

(Embodiment 1)
Hereinafter, the objective lens driving device according to Embodiment 1 of the present invention will be described with reference to the drawings. 1, 2, 3 (a), 3 (b), and 3 (c), F is a focusing direction, T is a tracking direction, K is a focusing direction F and a direction K perpendicular to the tracking direction T. The focusing direction F, the tracking direction T, and the direction K correspond to the directions of the coordinate axes in the three-dimensional orthogonal coordinate system.

  1 and 2, reference numeral 2 denotes a lens holder made of a formed resin. The objective lens 1 is mounted on the lens holder 2, and the position away from the objective lens 1 is substantially along the focusing direction F. A rectangular through hole is formed. A printed coil 3 is attached to a substantially central portion of the lens holder 2 in parallel to a plane including the focusing direction F and the tracking direction T.

  The printed coil 3 has a coil structure in which a conductive material is spirally attached around an axis parallel to the direction K on the substrate to form a coil structure, and the layers constituting the focusing coil portion 3a and the tracking coil portions 3b and 3c are arranged. Consists of two types of layers. The focusing coil portion 3a is disposed on the side closer to the objective lens 1, the tracking coil portions 3b and 3c are disposed on the side far from the objective lens 1, and the tracking coil portions 3b and 3c are wired in series.

  Further, the relay terminal plate 9 is fixed to each of two side surfaces perpendicular to the tracking direction T of the lens holder 2, and both end terminals of the focusing coil 3a formed on the printed coil 3 and the tracking coil portions 3b and 3c. Both end terminals are connected by soldering.

  Therefore, the objective lens 1, the lens holder 2, the print coil 3, and the relay terminal plate 9 constitute a movable body. The movable body has a symmetrical shape with respect to a plane that includes the optical axis of the objective lens 1 and is perpendicular to the tracking direction T, and the center of gravity of the movable body is on the line that intersects the surface of the printed coil 3 in the plane. It is set to be located.

  Reference numeral 4 denotes a first multipole magnet having a plurality of magnetic pole regions in the same plane, and is composed of two magnetic pole regions, a magnetic pole region 4a and a magnetic pole region 4b, which are separated by one magnetic field boundary line parallel to the tracking direction T. Reference numeral 5 denotes a second multipole magnet having a plurality of magnetic pole regions in the same plane, and includes two magnetic field boundary lines substantially parallel to the focusing direction F and one magnetic field boundary line parallel to the tracking direction T. It is composed of two magnetic pole areas, a quadrangular magnetic pole area 5a and a concave magnetic pole area 5b separated by a U-shaped magnetic field boundary formed in combination.

  The first multi-pole magnet 4 and the second multi-pole magnet 5 are arranged at opposing positions so as to sandwich the printed coil 3 with a gap. A second multipole magnet 5 is fixed to the base 6 via a mounting portion 6b on the side far from the objective lens. On the side close to the objective lens, the first multipole magnet 4 is disposed on the attachment portion 6a while being held by an external holding means such as a jig.

  When the action point of the electromagnetic force by the first multipole magnet 4 and the second multipole magnet 5 works in the focusing direction F or tracking direction T passing through the support center of the movable body, the tilt accompanying the movement of the movable body The occurrence of this is minimized. However, if the positional relationship between the magnet and the coil shifts due to the effect of assembly accuracy and other various adjustments, and the point of drive force does not pass through the support center of the movable body, a moment around the support center is generated. As a result, radial tilt and tangential tilt occur with the movement of the movable body. The generated tilt of the objective lens deforms the shape of the focused spot of the laser beam and causes optical aberration. Since this optical aberration is a major factor in deteriorating the recording characteristics, the production of the optical disk apparatus must prevent the tilt of the objective lens from occurring as much as possible, and the first arranged to sandwich the print coil 3. The positioning of the relative positions of the multipole magnet and the second multipole magnet is important.

  In the first embodiment, the first multipole magnet 4 is held from both sides by a jig or the like, and the second multipole magnet 5 fixed to the base 6 in advance is moved and adjusted while the relative position is adjusted. The width of the first multipole magnet 4 in the tracking direction is configured to be larger than the width of the attachment portion 6a so that one multipole magnet 4 can be fixed. With this configuration, the first multipole magnet 4 is not hidden by the attachment portion 6a when moving and adjusting in the tracking direction. Therefore, it is possible to easily adjust the relative position with respect to the opposing second multipole magnet, and to suppress the occurrence of the tilt described above.

  Here, the assembly means after the assembly of the minimum configuration capable of confirming the operating point of the driving force by the first magnet 4, the second magnet 5 and the printed coil 3, and all the components constituting the objective lens driving device. Does not mean completing the elements.

  Further, the means for fixing may be one using an adhesive or one using a stopper, and any means may be used.

  In the present embodiment, the structure for easily holding the magnet is realized by changing the width of the attachment portion 6a with respect to the first multipolar magnet 4, but the height can be changed or the attachment portion 6a can be changed. The first multipole magnet 4 may have a structure that can be easily held by a method such as adding a handle.

  Further, when it is not necessary to use a magnetic yoke or the like as the magnet attachment portion, a configuration in which the magnet is directly attached to a part of the base may be adopted. In this case, since the attachment portion can be manufactured integrally with the base, further material and process reduction effects can be obtained.

As described above, after the support center of the movable body and the action points of the driving forces of the first multipole magnet 4, the second multipole magnet 5, and the printed coil 3 are matched, the first multipole magnet 4 and The attachment portion 6a is adhered. The jig holding the first multipole magnet 4 is removed, and the remaining parts are assembled to complete the objective lens driving device. By adopting such a configuration, it is possible to easily adjust the displacement of the relative position of the magnet, which causes the occurrence of tilt after assembly, so there is no need to add a special mechanism, and the apparatus is capable of suppressing the occurrence of tilt. Can provide an excellent objective lens driving device that can be reduced in size and thickness (Embodiment 2)
Hereinafter, an objective lens driving apparatus according to Embodiment 2 of the present invention will be described with reference to the drawings. In addition, about the thing which has the structure similar to Embodiment 1, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  In the second embodiment, in the objective lens driving device having the configuration described in the first embodiment, the first multipole magnet 4 has a shape in which a part on both sides of the attachment portion 6a is notched. By adopting this shape, it is possible to adjust the movement in the tracking direction while holding the first multipole magnet through the notch with a jig or the like.

  With this configuration, even if the attachment portion 6a is larger than the first multipole magnet 4, the movement can be adjusted, and the relative position with respect to the second multipole magnet 5 can be easily positioned. Even when the mounting portion 6a must be configured larger than the first multipole magnet 4 due to insufficient strength of the base 6 or the like, the relative position can be determined without the need for adding a special mechanism.

  At this time, since the attachment portion 6a of the first magnet 4 has a structure in which holes other than those for passing through an external holding means such as a jig are formed, an adhesive or the like can be poured from the first multipolar magnet. 4 can be easily fixed from the attachment portion 6a side.

  When the widths of the first multipole magnet 4 and the attachment portion 6a are approximately the same, it is only necessary to provide notches on both sides of the attachment portion 6a, but if the width is wider, a through hole may be provided.

(Embodiment 3)
Hereinafter, a method of manufacturing the objective lens driving device according to Embodiment 3 of the present invention will be described with reference to the drawings. In addition, about the thing which has the structure similar to Embodiment 1, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  The third embodiment is characterized in that the objective lens driving device having the configuration described in the first embodiment is assembled by the following steps.

  First, the first multipole magnet 4 is held between both sides by, for example, a clip-type jig. This jig can be adjusted to move in at least one axial direction. Further, at least the second multipole magnet 5 is fixed to the base 6.

  It is preferable that the jig is inserted and held from the side opposite to the base 6 or the attachment portion 6a with the movable body interposed therebetween. It is good.

  Next, with respect to the base 6 to which the second multipole magnet 5 is fixed, the first multipole magnet 4 is movably disposed in the vicinity of the attachment portion 6a while being held by a jig, and the first multipole magnet 4 is disposed. The relative position of the first multipole magnet with respect to the second multipole magnet is adjusted so that the action point of the electromagnetic force generated by the second multipole magnet 5 coincides with the support center of the movable body. Specifically, the first multipole magnet 4 is moved and adjusted to a position where no tilt occurs when the movable body is moved in the tracking direction and the focusing direction.

  After positioning the first multipolar magnet 4, it is fixed to the attachment portion 6a with an adhesive.

  Finally, the jig holding the first multipole magnet 4 is removed, and the remaining structure is assembled to complete the objective lens driving device described in the first embodiment.

By using this manufacturing method, it is possible to easily adjust the displacement of the relative position of the magnet that causes tilt after assembly, so there is no need to add a special mechanism, and downsizing while suppressing the occurrence of tilt It is possible to provide an excellent objective lens driving device that can be thinned. Here again, when assembling, the assembly of the minimum configuration that can confirm the operating point of the driving force by the first magnet 4, the second magnet 5, and the printed coil 3 It means the latter, and does not mean that all elements constituting the objective lens driving device are completed.

  Here, the external holding means such as a jig for holding the first multipole magnet in a movable manner can move the held object in at least one axial direction, and holds the first multipole magnet while holding the first multipole magnet. As long as the movable part including the multi-pole magnet 5 and the printed coil 3 can be assembled, the shape and the holding method are not limited.

  When using a coil unit in which the tracking coil and focusing coil are printed and superimposed on each other as described above, or a coil unit in which each coil is printed on the front and back of the board and arranged as an integral structure, the driving force of the magnet and coil is used. Therefore, the present invention exerts an even higher effect.

  Since the objective lens driving device of the present invention can be reduced in size and thickness, for example, it can contribute to reduction in size and thickness of a light disk drive.

1 is an exploded perspective view showing a configuration of an objective lens driving device in an embodiment of the present invention. The top view which shows the structure of the objective lens drive device in embodiment of this invention The objective lens drive device in embodiment of this invention is shown, (a) transparently represented the positional relationship of the 2nd multipolar magnet at the time of seeing (b) from the direction of arrow U, and a tracking coil part. Schematic side view, (b) is a schematic plan view for explaining the positional relationship between the first multipolar magnet, the second multipolar magnet and the printed coil in FIG. 2, and (c) is (b). Schematic side view transparently showing the positional relationship between the first multipolar magnet and the focusing coil portion when viewed from the direction of arrow V An exploded perspective view showing a configuration of a conventional objective lens driving device The top view which shows the structure of the conventional objective lens drive device The structure of the conventional objective lens drive device is shown, (a) is a schematic side view transparently showing the positional relationship between the magnet and the focusing coil when (b) is viewed from the direction of arrow U, (b). Is a schematic plan view for explaining the positional relationship between a magnet, a focusing coil, and a tracking coil in a conventional objective lens driving device, and (c) is a magnet and a tracking coil when (b) is viewed from the direction of arrow V. Schematic side view showing the positional relationship of

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Objective lens 2 Lens holder 3 Print coil 3a Focusing coil part 3a1, 3a2 Effective coil area | region 3b Tracking coil part 3b1, 3b2 Effective coil area | region 3c Tracking coil part 3c1, 3c2 Effective coil area | region 4 1st multipole magnet 4a, 4b Magnetic pole Region 5 Second multi-pole magnet 5a, 5b Magnetic pole region 6 Base 6a Mounting portion 6b Mounting portion 7a-7d Wire 8 Suspension holder 9 Relay terminal plate 10 Fixed substrate 100 Objective lens 101 Lens holder 102 Focusing coil 103 Tracking coil 104, 105 Magnet 106 Base 107a to 107d Wire 108 Suspension holder 109 Relay terminal board 110 Fixed substrate

Claims (7)

A movable body having an objective lens, a lens holder for holding the objective lens, a coil portion including a focusing coil and at least one tracking coil, a first magnet, and a second facing the first magnet. And a base on which the first magnet and the second magnet are fixed substantially in parallel so as to sandwich the coil portion of the movable body, and the coil portion of the movable body includes In the objective lens driving device that is movably supported through a gap between the first magnet and the second magnet, a width of the first magnet in the tracking direction is provided on the base. The first magnet is configured to be larger than the width of the attachment portion for attaching the magnet, and the first magnet with respect to the second magnet. An objective lens driving device, wherein a position of relative is adjustably configured in the tracking direction. A movable body having an objective lens, a lens holder for holding the objective lens, a coil portion including a focusing coil and at least one tracking coil, a first magnet, and a second facing the first magnet. And a base on which the first magnet and the second magnet are fixed substantially in parallel so as to sandwich the coil portion of the movable body, and the coil portion of the movable body includes In the objective lens driving device that is movably supported through a gap between the first magnet and the second magnet, the mounting portion of the first magnet provided on the base is the first magnet. Having a notch or a through hole so that the first magnet can be held from the mounting portion side, and the first magnet with respect to the second magnet. An objective lens driving apparatus characterized by Tsu City of relative position is adjustable configuration to the tracking direction. 3. The objective lens drive according to claim 1, wherein the base has a through-hole through which the external holding means can pass in order to hold the first magnet by the external holding means that does not constitute the objective lens driving device. apparatus. An optical disk drive device using the objective lens driving device according to claim 1. An information processing apparatus using the optical disk drive device according to claim 4. A music playback device using the optical disk drive device according to claim 4. A movable body having an objective lens, a lens holder for holding the objective lens, a coil portion including a focusing coil and at least one tracking coil, a first magnet, and a second facing the first magnet. And a base that is fixed substantially in parallel with an interval so that the first magnet and the second magnet sandwich the coil portion of the movable body,
In the manufacturing method of an objective lens driving device in which the coil portion of the movable body is movably supported between the first magnet and the second magnet via a gap, the first magnet is used as the objective lens driving device. A step of holding the first magnet, the second magnet fixed in advance, and the coil portion of the movable body, the step of holding the first magnet, the second magnet fixed in advance, and the coil portion of the movable body; Adjusting and positioning the relative position of the first magnet with respect to at least one of the magnet and the coil portion of the movable body; fixing the first magnet to the mounting portion after positioning the first magnet; A method of manufacturing an objective lens driving device, comprising: releasing the holding of the first magnet and removing the external holding means.

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