JP2006134437A - Objective lens driving device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an objective lens driving device capable of thinning an optical pickup by shortening the length of a lens holder in a height direction regarding a 6-wire supported type objective lens driving device. <P>SOLUTION: The objective lens driving device 1 having 6 wires 21, 21, 22, 22, 23 and 23 and designed to support a lens holder 15 in a movable state and to supply a current to the coil of the lens holder 15 thereby driving the lens holder 15 in 3 axial directions. On one side face of the lens holder 15, the fixed parts A and C of the upper and lower two wires 21 and 23 are arranged on a straight line orthogonal to the wires, and the fixed part B of one center wire 22 is arranged by being shifted from the straight line. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an objective lens driving apparatus that performs minute position correction of an objective lens that is disposed opposite to an optical disk with an optical pickup, and relates to a technique that is useful for being capable of driving in three axial directions.

  In an optical pickup that records and reproduces data by irradiating an optical disk with a laser beam, the objective lens disposed opposite to the optical disk is placed in the focus direction, and the tracking direction (radial direction of the disk) intersecting the data track row of the optical disk. And an objective lens driving device (also referred to as a lens actuator) for correcting the position of the objective lens.

  In recent years, in addition to the focus direction and the tracking direction, there are an increasing number of lens actuators that drive in the triaxial direction of the tilt angle direction corresponding to the warp of the disk.

  As a structure of the lens actuator, a lens holder that cantilever-supports a lens holder that holds an objective lens with a plurality of wires is the mainstream. And while providing an electromagnetic coil in a lens holder, a magnet is arrange | positioned in the vicinity of the lens holder of a base frame side, an electromagnetic force is generated by supplying an electric current to said electromagnetic coil from said wire, and a lens holder is driven. In the case of driving in the three-axis direction, as shown in FIG. 4, a configuration in which six wires W in total on the left and right are stretched on the lens holder 81 and three independent currents can be supplied to the electromagnetic coil. Is done.

Conventionally, various techniques relating to such a six-wire support type lens actuator have been proposed (for example, Patent Documents 1 to 6).
JP 2000-242944 A JP 2002-352456 A JP 2003-109234 A JP 2002-245650 A JP 2003-173557 A JP 2003-217149 A

  Since optical disk drives are mounted on various devices such as notebook computers and portable video devices, there is always a demand for miniaturization and thinning of optical pickups.

  In a general optical pickup, various optical processes are performed while a laser beam is propagated in a horizontal direction by a plurality of optical components, and the laser beam is raised in a vertical direction by a rising mirror and transmitted through an objective lens. It is configured to irradiate to. Accordingly, the objective lens and the lens actuator are stacked on the layer on which a plurality of optical components are disposed. Therefore, an increase in the thickness of the lens actuator directly leads to an increase in the thickness of the optical pickup.

  However, in the conventional 6-wire support type lens actuator, as shown in FIG. 4, the three wires W had to be soldered in parallel on the side surface of the lens holder 81. It is necessary to increase the height of 81, which increases the thickness of the lens actuator 80 and the optical pickup.

  An object of the present invention is to provide an objective lens driving device capable of reducing the thickness of an optical pickup by shortening the length of a lens holder in a six-wire support type lens actuator. .

  In order to achieve the above object, the present invention provides an objective lens driving apparatus that drives an objective lens that focuses laser light on a recording surface of an optical disc in a focus direction, a tracking direction, and a tilt angle direction, and includes a plurality of electromagnetic coils. A lens holder that holds the objective lens, a magnet that is fixed at a position near the lens holder and exerts a driving force on the lens holder by electromagnetic action with the electromagnetic coil, one end side of the lens holder and the other end side of the base frame side And six wires which are fixed (for example, soldered) to support the lens holder in a movable state and supply current to the electromagnetic coil, and the six wires are arranged on one side and the other of the lens holder. Are attached to each side surface of the lens holder, and three screws on one side surface of the lens holder. And a configuration in which two anchor portion adjacent one of the fixed portion of Ya has become arrangement alternately deviated from a straight line perpendicular to the wire in the extending direction of the wire.

  When soldering three wires on a straight line orthogonal to the wires as in the conventional example of FIG. 4, it is necessary to set the pitch interval of the wires to 2 mm or more so that the solders of the three fixing portions do not stick. The length of the lens holder becomes longer. On the other hand, according to the present invention described above, since the fixing portion is displaced from a straight line orthogonal to the wire, the interval between the wire fixing portions can be widened even if the interval between the wires is reduced. Thereby, the space | interval of a wire can be narrowed and the length of a lens holder can be shortened.

  Specifically, the three wires fixed to each side surface of the lens holder are stretched substantially parallel to each other, and the fixing portions of the upper and lower two wires on one side surface of the lens holder are perpendicular to the wires. It is good to make it the arrangement | positioning which is arrange | positioned on 1 straight line, and the fixing | fixed part of one middle wire shifted | deviated from the said 1st straight line.

  According to such a configuration, since the fixing portions of the two upper and lower wires are on a straight line orthogonal to the wires, all the three fixing portions are deviated from the straight line orthogonal to the wires. Thus, each movement of the lens holder in the focus direction, tracking direction, and tilt angle direction can be stably obtained.

  Specifically, among the three wires fixed to the respective side surfaces of the lens holder, the fixing portion on the base frame side of the upper and lower two wires is arranged on a second straight line perpendicular to the wires, and is in the middle. It is preferable that the fixing portion on the base frame side of the one wire be shifted in the direction in which the wire length becomes longer than on the second straight line.

  According to such a configuration, the distance between the wires can be reduced even on the base frame side, and the middle wire length is increased, so that the acting force of the middle wire on the lens holder is made smaller than that of the upper and lower wires. I can do it. Accordingly, it is possible to stably obtain each movement of the lens holder in the focus direction, tracking direction, and tilt angle direction. Furthermore, since the natural frequency of the middle wire is different from that of the upper and lower wires, unnecessary resonance of the lens holder can be made difficult to occur.

  As described above, according to the present invention, the length of the lens holder can be shortened, so that there is an effect that the optical pickup can be made smaller and thinner accordingly.

  Further, the six-wire support type has an effect that a stable movement of the lens holder can be obtained and an unnecessary resonance mode of the lens holder can be removed.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a perspective view showing a lens actuator according to an embodiment of the present invention, FIG. 2 is a diagram showing a pattern of a soldering land of a fixed substrate and a lens holder to which a wire is soldered, and FIG. 3 is an electromagnetic provided in the lens holder. It is the perspective view which showed arrangement | positioning of a coil.

  A lens actuator (objective lens driving device) 1 according to this embodiment includes a base frame 10, a fixed block 11 screwed to the base frame 10, and a fixed substrate for fixing wires fixed to the fixed block 11. 12, 12, 6 wires 21, 22, 22, 22, 23, 23, magnets 13, 13 fixed to the standing pieces 10 a, 10 b of the base frame 10, and 6 in a state of being lifted from the base frame 10 The lens holder 15 is supported in a movable state by the wires 21 to 23, and the objective lens 16 is held at the upper center of the lens holder 15.

  The lens holder 15 has a substantially rectangular parallelepiped shape as a rough shape, and a circular hole 15a for allowing laser light to pass through is provided at the center from the top surface to the bottom surface, and the objective lens 16 is fixed to the upper portion. Also, flat coils 31 and 31 for tracking drive are fixed to the surfaces facing the magnets 13 and 13, and the electric wires are horizontally disposed at positions on both the left and right sides of the lens holder 15 avoiding the circular holes 15a. Winding coils 32 and 33 for focus drive and tilt angle drive are provided. There are various forms of arrangement of coils and magnets for driving the lens holder 15 in the three-axis directions, and the above form is only an example.

  A solder land pattern to which solder is fixed is formed on the left and right side surfaces of the lens holder 15, and wires 21 to 23 are soldered to the solder land. Actually, the substrates 15 b and 15 b on which solder land patterns are formed are attached to both side surfaces of the lens holder 15.

  Further, the wires 21 to 23 and the coils 31, 31, 32, and 33 are electrically connected through this pattern, and one set of coils 31 for tracking driving is provided through two sets of wires 21 to 23. , 31 and two coils 32 and 33 for focus and tilt driving are supplied with independent currents. The protrusions 15c formed on the side of the solder land pattern in FIG. 1 position the wires 21 when the wires 21 are soldered.

  The three wires 21, 22, 23 soldered to the same side surface of the lens holder 15 are stretched almost in parallel, and the other ends are soldered to solder lands formed on the fixed substrates 12, 12. Yes.

  The fixed block 11 is provided with gel boxes 11a and 11a filled with a gel material in a range where the wires 21 to 23 extend from the fixed substrates 12 and 12, and vibrations of the wires 21 to 23 are buffered by the gel material. It is like that.

  As shown in FIGS. 1 and 2, in the lens actuator 1 of this embodiment, the solder land pattern on the side surface of the lens holder 15 is such that the solder lands A and C for fixing the upper and lower wires 21 and 23 are wires. On the other hand, the solder land B for fixing the middle wire 22 is provided at a position shifted from the straight line in the direction in which the wire 22 extends.

  The solder land pattern of the fixed substrate 12 is such that the solder lands L and N for fixing the upper and lower wires 21 and 23 are provided on a straight line perpendicular to the wire 21, while the solder land for fixing the middle wire 22 is fixed. M is provided at a position greatly deviated from the straight line in the direction in which the wire 22 becomes longer.

  When soldering wires, the diameter of the solder lands and the distance between the two solder lands must be designed to be a certain length or more due to restrictions on the soldering work. When arranged in a straight line in the height direction, the pitch interval of each wire becomes 2 mm or more, and as a result, the length of the lens holder becomes long. However, according to the solder land pattern of this embodiment, the adjacent solder lands are arranged in a staggered manner so that the pitch interval between the wires 21 to 23 is shorter than 2 mm, and the lens holder Can be shortened.

  Further, the upper and lower wires 21 and 23 are equal in length, and are arranged in a line perpendicular to the wires together with the solder lands A and C on the lens holder 15 side and the solder lands L and N on the fixed substrate 12 side. Therefore, it is possible to stably obtain each movement of the lens holder 15 in the focus direction, tracking direction, and tilt angle direction.

  Furthermore, since the middle wire 22 is configured to be 1.3 times longer than the upper and lower wires 21 and 23, the acting force on the lens holder 15 is weaker than that of the upper and lower two wires 21 and 23. Each movement of the lens holder 15 in the focus direction, tracking direction, and tilt angle direction can be stably obtained.

  Further, since the natural frequency of the middle wire 22 is different from that of the upper and lower two wires 21 and 23, an unnecessary resonance mode of the lens holder 15 can be removed. For example, when six wires have the same conditions (length, wire diameter, material, etc.), there are two pitching modes, one for each centering on the center of the upper and lower surfaces of the lens holder 15 as natural vibration modes. However, one of these can be removed by the above configuration.

  The present invention is not limited to the above-described embodiment. For example, the detailed structure shown in the embodiment such as the specific shape of the lens holder and the specific pattern shape of the solder land is the gist of the invention. As long as it does not deviate from the above, it can be appropriately changed.

It is a perspective view which shows the lens actuator of embodiment of this invention. It is a figure which shows the pattern of the solder land of the fixed board | substrate with which a wire is soldered, and a lens holder. It is the perspective view which showed arrangement | positioning of the electromagnetic coil provided in a lens holder. It is a perspective view which shows the conventional 6 wire support type lens actuator.

Explanation of symbols

1 Lens actuator (objective lens drive device)
DESCRIPTION OF SYMBOLS 10 Base frame 11 Fixed block 12 Fixed board 13 Magnet 15 Lens holder 16 Objective lens 21-23 Wire 31-33 Coil A-C Solder land on the lens holder side L-N Solder land on the base frame side

Claims (5)

In an objective lens driving device that drives an objective lens that focuses laser light on the recording surface of an optical disc in the focus direction, tracking direction, and tilt angle direction,
A lens holder having a plurality of electromagnetic coils and holding the objective lens;
A magnet that is fixed at a position near the lens holder and exerts a driving force on the lens holder by electromagnetic action with the electromagnetic coil;
One end side is fixed to the lens holder and the other end side is fixed to the base frame side by solder to support the lens holder in a movable state and supply six currents to the electromagnetic coil,
Three of the six wires are fixed to one side surface and the other side surface of the lens holder, and these three wires are respectively stretched in parallel.
On one side surface of the lens holder, a fixing portion of two of the three wires is arranged on a first straight line orthogonal to the wire, and a fixing portion of the remaining one wire is on the first straight line. From the direction of the wire extension,
Further, the fixing portion of the two wires is arranged on a second straight line orthogonal to the wire on the base frame side, and the wire fixing portion of the remaining one wire is longer than the second straight line. An objective lens driving device, wherein the objective lens driving device is arranged so as to deviate. In an objective lens driving device that drives an objective lens that focuses laser light on the recording surface of an optical disc in the focus direction, tracking direction, and tilt angle direction,
A lens holder having a plurality of electromagnetic coils and holding the objective lens;
A magnet that is fixed at a position near the lens holder and exerts a driving force on the lens holder by electromagnetic action with the electromagnetic coil;
One end side is fixed to the lens holder, and the other end side is fixed to the base frame side, and the lens holder is supported in a movable state and includes six wires for supplying current to the electromagnetic coil,
Three of the six wires are fixed to one side surface and the other side surface of the lens holder, and two adjacent ones of the fixing portions of the three wires on one side surface of the lens holder. An objective lens driving device characterized in that the fixing portions are staggered in a direction in which the wire extends from a straight line orthogonal to the wire.   The three wires fixed to each side surface of the lens holder are stretched substantially in parallel, and the fixing portions of the upper and lower two wires on one side surface of the lens holder are arranged on a first straight line perpendicular to the wires. 3. The objective lens driving device according to claim 2, wherein a fixing portion of one middle wire is arranged so as to be shifted from the first straight line.   4. The objective lens driving device according to claim 2, wherein the six wires are fixed to the lens holder with solder.   Of the three wires fixed to each side surface of the lens holder, the fixing portions on the base frame side of the two upper and lower wires are arranged on a second straight line orthogonal to the wires, and the base of the one wire in the middle 5. The objective lens driving device according to claim 2, wherein the fixing portion on the frame side is arranged so as to be shifted in a direction in which the wire length becomes longer than on the second straight line.

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