KR100510545B1 - Optical pickup actuator capable of driving tilt and optical recording and/or reproducing apparatus employing it - Google Patents

Abstract

Disclosed are an optical pickup actuator including a lens holder mounted on an objective lens and movably supported relative to a base by a suspension, and a magnetic circuit for driving the objective lens, and an optical recording and / or reproducing apparatus employing the objective lens. .

The magnetic circuit of the disclosed optical pickup actuator includes a pair of single pole magnets fixed to the base to face each other; A focus coil mounted to the lens holder so as to be positioned between the pair of single pole magnets; A plurality of tracking coils located on the side of the focus coil facing the single pole magnet; And a plurality of tilt coils positioned above and / or below the focus coil when the direction of the center axis of the objective lens is referred to as an up and down direction.

The disclosed optical pick-up actuator is capable of both symmetrical and asymmetrical types, and uses single-pole magnets, and enables three-axis driving by limiting the number of single-pole magnets to two, thereby reducing material costs, and reducing the cost of slim and thicker shapes. All are also applicable.

Description

Optical pickup actuator capable of driving tilt and optical recording and / or reproducing apparatus employing it}

The present invention relates to an optical pickup actuator and an optical recording and / or reproducing apparatus employing the same, and more particularly, to a tilt-driven optical pickup actuator and an optical recording employing the same, which can be manufactured at low cost by reducing the number of magnets. And / or a playback device.

An optical pickup is an apparatus which is employed in an optical recording and / or reproducing apparatus to record and / or reproduce information on an optical disk in a non-contact manner while moving in a radial direction of an optical disk which is an optical information storage medium.

This optical pickup requires an actuator for driving the objective lens in the tracking direction, the focus direction and / or the tilt direction so that the light emitted from the light source is formed as a light spot at the correct position on the optical disc. Here, the tracking direction drive refers to adjusting the objective lens in the radial direction of the optical disc so that an optical spot can be formed at the track center.

The optical pickup actuator is basically driven in a tracking direction and a focus direction, that is, two-axis drive. In recent years, the numerical aperture of the objective lens is increased and the wavelength of the laser light source is shortened to realize the high density optical storage device, thereby reducing the tilt direction of the optical pickup actuator. To this end, in addition to the conventional two-axis driving, that is, driving in the focusing direction and tracking direction, an optical pickup actuator of a three-axis driving type capable of driving in the tilt direction, in particular, the radial tilt direction is required. As described above, a three-axis optical pickup actuator capable of driving in the tilt direction in addition to the focusing direction and the track direction driving is called a tilt driving optical pickup actuator.

Tilt-driven optical pickup actuators are generally designed to design four-sided magnetic circuits. Here, the four-sided magnetic circuit means a structure in which a drive coil and a magnet are arranged on four sides of the lens holder.

1 is a plan view schematically showing an example of a conventional tilt drive optical pickup actuator.

Referring to the drawings, the conventional tilt drive optical pickup actuator includes a lens holder 2 on which the objective lens 1 is mounted, and an entire movable portion including the lens holder 2 with respect to a base (not shown). F) and a plurality of wires 6, one end of which is coupled to the lens holder 2 and the other end of which is fixed to the holder 3 provided on the base 9 so as to move in the tracking direction T, and driving the movable part. It consists of four sided magnetic circuits for use.

Four wires 6 serving as a suspension for supporting the entire movable part with respect to the base are provided. In FIG. 1 only two of the four wires 6 are shown. In FIG. 1, reference numeral 9 is a wire used as a current application passage for tilt direction driving.

The conventional magnetic circuit is provided with a pair of focus coils 4a and 4b provided at both ends of the lens holder 2 in the radial direction of the optical disk, and provided at both sides of the lens holder 2 in the tangential direction of the optical disk. A magnet for generating an electromagnetic force for driving the movable part by interaction with a pair of tracking coils 4c and 4d and current flowing through the focus coil and tracking coils 4a, 4b, 4c and 4d. 5a), 5b), 5c), 5d, and the yoke 8, respectively.

In the conventional tilt drive optical pickup actuator having the above configuration, when the current is applied to the focus coils 4a, 4b and the tracking coils 4c, 4d, the focus coils 4a, 4b and the tracking coils are applied. The electromagnetic force is applied to the focus coils 4a, 4b and the tracking coils 4c, 4d by the interaction of the current flowing through the 4c, 4d and the magnetic flux from the magnets 5a, 5b, 5c, and 5d. This action causes the entire movable portion to move in the focusing direction F and the tracking direction T, whereby the objective lens 1 mounted on the lens holder 2 moves in the focusing direction F and the tracking direction T. Is moved).

In addition, when a current is applied to each of the pair of focus coils 4a and 4b so that electromagnetic forces act in the opposite directions to the pair of focus coils 4a and 4b, the movable portion moves in the radial tilt direction. The objective lens 1 mounted on the holder 2 moves in the radial tilt direction.

In this way, the focusing and tilt driving are in parallel with the central axis of the objective lens 1, so that the same magnets 5a, 5b and coils 4a, 4b are used. That is, when a current having the same value is applied to a pair of focus coils 4a and 4b, a focus motion with a constant displacement occurs, and a tilt motion occurs when a current having the same magnitude but opposite directions is input.

By the way, the conventional tilt drive optical pickup actuators as described above are provided with four coils 4a, 4b, 4c, and 4d, which are respectively wound in advance, on four sides of the lens holder 2, and all four independent Since it has a four-sided use magnetic circuit comprising magnets 5a, 5b, 5c, 5d, four independent magnets 5a, 5b, 5c, 5d and four independent coils 4a ( 4b) (4c) (4d) due to the increase in the number of parts and production cost due to the use of the problem that the productivity is deteriorated.

The use of the pre-wound coil requires a process of winding the coil and a process of attaching the wound process to the lens holder, so that the number of manufacturing processes is high and the defect rate is higher than that of the direct winding, and four independent magnets are required. Because.

In addition, in the conventional tilt drive optical pickup actuator, the magnet is positioned to face the four surfaces of the lens holder 2, and the focus coil and the tracking coil are also located on the four sides of the lens holder 2, respectively, so that between the coils There is a complicated wiring.

The present invention has been made to solve the problems of the conventional optical pick-up actuator as described above, and has a low-cost magnetic circuit capable of driving in the tilt direction in addition to the focus direction and the tracking direction using only two single-pole magnets. An object of the present invention is to provide a tilt-driven optical pickup actuator and an optical recording and / or reproducing apparatus employing the same.

In order to achieve the above object, the present invention includes a lens holder is mounted on the objective lens, the lens holder is movably supported relative to the base by the suspension; And a magnetic circuit for driving the objective lens, the optical pickup actuator comprising: a pair of single-pole magnetized magnets fixed to the base to face each other; A focus coil mounted to the lens holder to be positioned between the pair of single pole magnets; A plurality of tracking coils located on a side of the focus coil facing the single pole magnet; And a plurality of tilt coils positioned above and / or below the focus coil when the direction of the center axis of the objective lens is referred to as a vertical direction.

According to an embodiment of the present invention, the pair of single-pole magnetized magnets are fixedly installed relative to the base so as to face opposite sides of the lens holder, the focus coil is wound around the lens holder, and the tracking coil is The tilt coil may be installed at a side of the lens holder facing the single pole magnet and the tilt coil may have a symmetrical structure installed at an upper side and / or a lower side of the lens holder.

In this case, a plurality of coils may be formed to wind the tracking coil on the lens holder, and the tracking coil may be wound on the other coil, or the tracking coil may be attached to the lens holder.

Skeins are formed on both sides of the lens holder in the radial direction of the objective lens of the upper and / or lower part, and the tilt coil may be wound on a pair of tufts formed on the upper and / or lower part of the lens holder, respectively. have.

In the lens holder, the mounting portion for installing the objective lens is formed to be spaced apart from the tilt coil disposed on the upper portion of the lens holder, so that the effect of heat on the objective lens can be reduced.

The lens holder is preferably provided with at least one heat transfer blocking hole to reduce the transfer of heat generated from the focus coil, tracking coil and / or tilt coil to the objective lens.

According to another embodiment of the present invention, the objective lens is mounted on one side of the lens holder, the pair of single-pole magnets are fixed to the base to face each other on one side of the objective lens, the focus coil, tracking The coil assembly including a coil and a tilt coil may be an asymmetrical structure mounted on the other side of the lens holder such that the coil assembly is positioned between the pair of single pole magnets.

Here, the coil assembly may further include a bobbin in which at least the focus coil is aligned and wound.

A bobbin is formed on the bobbin so as to wind the tracking coil, and the tracking coil may be wound on a bobbin formed on the bobbin.

Skeins are formed on both sides of the bobbin along the radial direction of the objective lens of the upper and / or lower parts, and the tilt coil may be wound around a pair of tufts formed on the upper and / or lower parts of the bobbin, respectively.

Alternatively, the coil assembly may have a structure in which a bulk coil wound in advance of the focus coil, the tracking coil, and the tilt coil is used, and the tracking coil and the tilt coil are attached to the focus coil.

Here, to guide the magnetic flux, a bridge located above the magnetic circuit; may further include.

And a pair of outer yokes extending from the bridge and supporting the pair of unipolar magnets and / or a pair of inner yokes extending from the bridge and disposed inside the tilt coil of the coil assembly. have.

Alternatively, a pair of outer yokes formed in the base and on which the monopole magnet is mounted; And a pair of inner yokes formed in the base to be positioned inside the tilt coil.

The tracking coil may be located closer to the unipolar magnet magnet than the focus coil, or the focus coil may be located closer to the unipolar magnet magnet than the tracking coil.

In order to achieve the above object, the present invention includes a lens holder is mounted on the objective lens, the lens holder is movably supported relative to the base by the suspension; And a magnetic circuit for driving the objective lens, wherein the magnetic circuit comprises: a pair of single pole magnets fixed to the base to face each other on one side of the objective lens; A pair of focus coils disposed in the lens holder so as to be positioned between the pair of single pole magnets, the pair of focus coils arranged in a direction crossing the direction in which the pair of single pole magnets are disposed, and the pair of pairs of facing single pole magnets It comprises a plurality of tracking coils located on at least one side of the focus coil, the coil assembly mounted on the lens holder to be located between the pair of single-pole magnet magnets; characterized in that the asymmetric structure including a.

Here, the coil assembly may have a structure in which a bulk coil coiled in advance by the focus coil and the tracking coil is used and the plurality of tracking coils are attached to the pair of focus coils.

In order to achieve the above object, the present invention is provided with an actuator for driving an objective lens, the optical pickup is installed to be movable in the radial direction of the optical information storage medium to reproduce the information recorded on the optical information storage medium or to record the information and; An optical recording and / or reproducing apparatus, comprising: a lens holder mounted with an objective lens and movably supported relative to a base by suspension; A pair of single pole magnets fixed to the base to face each other, a focus coil installed on the lens holder to be positioned between the pair of single pole magnets, and a side of the focus coil facing the single pole magnet A magnetic circuit including a plurality of tracking coils and a plurality of tilt coils positioned above and / or below the focus coil when the direction of the center axis of the objective lens is a vertical direction; Characterized in that it comprises a.

Here, the actuator is fixed to the base such that the pair of single-pole magnet magnets are located facing both sides of the lens holder, the focus coil is wound around the lens holder, the tracking coil is the single-pole magnet magnet The tilt coil may be installed at a side of the lens holder facing the lens holder, and the tilt coil may have a symmetrical structure installed at upper and / or lower portions of the lens holder.

In addition, the actuator, the objective lens is mounted on one side of the lens holder, the pair of single-pole magnetized magnet is fixed relative to the base to face each other on one side of the objective lens, the focus coil, tracking coil and tilt The coil assembly including a coil may be an asymmetrical structure mounted on the lens holder such that the coil assembly is positioned between the pair of single pole magnets.

In order to achieve the above object, the present invention is provided with an actuator for driving an objective lens, the optical pickup is installed to be movable in the radial direction of the optical information storage medium to reproduce the information recorded on the optical information storage medium or to record the information and; An optical recording and / or reproducing apparatus, comprising: a lens holder mounted with an objective lens and movably supported relative to a base by suspension; A pair of single pole magnets fixed to the base so as to face each other at one side of the objective lens, and installed in the lens holder so as to be located between the pair of single pole magnets, and the direction in which the pair of single pole magnets are arranged A pair of focus coils disposed in a cross direction and a plurality of tracking coils positioned on at least one side of the pair of focus coils facing the single pole magnet, and located between the pair of single pole magnets Including a coil assembly mounted on the lens holder, a magnetic circuit for driving the objective lens; characterized in that the asymmetric structure including a.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the tilt-driven optical pickup actuator and optical recording and / or reproducing apparatus employing the same according to the present invention.

In the optical pickup actuator according to the present invention, as shown in FIGS. 2, 9, 15, and 16, by using a pair of single-pole magnetized magnets, a magnetic circuit is configured to implement focus, track, and tilt servos. Has its features.

In the optical pickup actuator according to the present invention, as shown in FIGS. 2, 9 and 15, the magnetic circuit includes a pair of single-pole magnetized magnets, a focus coil, a plurality of tracking coils and an objective lens positioned on the side of the focus coil. When the direction of the central axis of the vertical direction, it may be configured to include a plurality of tilt coils located above and / or below the focus coil.

In addition, in the optical pickup actuator according to the present invention, as shown in Fig. 16, the magnetic circuit includes a pair of single pole magnets, a pair of focus coils and a pair of cross coils arranged in a direction crossing with the pair of single pole magnets. It may comprise a plurality of tracking coils located on the focus coil side of the.

2 is a perspective view schematically showing the optical pickup actuator according to an embodiment of the present invention, Figure 3 is a perspective view showing only the lens holder of Figure 2, Figure 4 is a plan view of Figure 2, Figure 5 is a AA line cross-sectional view.

2 to 5, the optical pickup actuator according to an embodiment of the present invention, the lens holder 20 on which the objective lens 10 is mounted, one end is coupled to the lens holder 20, the other end of the base A suspension 13 fixed to a holder (not shown) provided on one side of the 11 and movably supporting the lens holder 20 with respect to the base 11, and installed in the lens holder 20 and the base 11. It is configured to include a magnetic circuit, and is a symmetrical structure.

In addition, the magnetic circuit includes a pair of single-pole magnetized magnets 31 fixedly fixed to the base 11 so as to face both sides of the lens holder 20 in parallel with the radial direction, and a focus wound around the lens holder 20. The plurality of tracking coils 35 provided on the side of the lens holder 20 facing the coil 33, the single-pole magnetized magnet 31, and the plurality of tilt coils 37 provided on the upper portion of the lens holder 20. It is configured to include. The pair of single-pole magnet magnets 31 are provided on the base 11 so as to face both sides of the lens holder 20 in the tangential direction of the optical disk of the optical information storage medium.

Four suspensions 13 are provided and are preferably used as a wire for applying current for tracking control and focus control. The optical pickup actuator according to an embodiment of the present invention further includes two wires 14 for applying a tilt driving current in addition to the four suspensions 13.

The optical pickup actuator according to an embodiment of the present invention, in addition to having a pair of single-pole magnetized magnets 31, allows the lens holder 20 to wind at least some coils directly to the lens holder 20. It is characterized in that a coil is formed in the coil and the coil is wound directly on the coil.

2 to 5, the body of the lens holder 20 may be formed in a skein structure to directly wind the focus coil 33, and both the tracking coil 35 and the tilt coil 37 may be directly wound. An example of forming the tufts 36 and 38 on the lens holder 20 is illustrated.

The focus coil 33 is wound around the lens holder 20 so that an electromagnetic force capable of moving the entire moving part of the actuator in the focus direction is generated by interaction with the pair of single-pole magnetized magnets 31.

The body of the lens holder 20 may be formed in a skein structure so that the focus coil 33 may be directly wound around the lens holder 20. Here, instead of forming the lens holder 20 body in a skeletal structure, the winding positions 23 and / or the tracking coils 35 for installing the suspension 13 may be wound around the winding position of the focus coil 33. It is also possible to limit by the tuft 36 for.

When the central axis direction of the objective lens 10 is referred to as a vertical direction, that is, a focus direction, and a side close to the optical information storage medium is referred to as an upper side and an opposite side as a lower side, the focus coil 33 is a monopole magnet 31 By the magnetic field generated by, according to the direction of the current flowing in the focus coil 33 and the direction of the magnetic flux generated in the single-pole magnet magnet 31, the electromagnetic force is applied in the up or down direction by the Fleming's left hand law, As a result, the entire movable portion of the optical pickup actuator according to the present invention moves in the focus direction.

On the other hand, as shown in Figures 2 to 5, the lens holder 20 has a coil 36 so that the tracking coil 35 can be installed on the side of the lens holder 20 facing the single-pole magnet magnet 31 It is preferred that the tracking coil 35 is wound directly on the tuft 36. Only a part of the tracking coil 35 faces the single pole magnet 31 in front so that the tracking coil 35 can generate an electromagnetic force for control in the tracking direction by the interaction with the single pole magnet 31. Is arranged to. In addition, the tracking coil 35 and the tuft 36 for winding the same, as shown in FIG. 2 so that the entire movable part of the actuator can be stably moved in the tracking direction, the lens holder 20 side by side in the radial direction It is preferable that a pair is provided on both sides. That is, it is preferable that all four tracking coils 35 are provided.

2 to 5 illustrate a case in which the tracking coil 35 is wound outside the focus coil 33. 2 to 5, when the tracking coil 35 is wound outside the focus coil 33, the tracking coil 35 is located closer to the unipolar magnet magnet 31, so that the tracking sensitivity is better. can do.

Alternatively, the optical pick-up actuator according to the present invention, as shown in FIG. 6, winds the focus coil 33 outside the tracking coil 35 so that the focus coil 33 is located closer to the unipolar magnet 31. It is also possible to be configured to. In this way, when the focus coil 33 is wound outside the tracking coil 35, the focus sensitivity can be further increased. As such, the structure in which the focus coil 33 is wound outside the tracking coil 35 may include a structure of one embodiment of the present invention as shown in FIGS. 2 to 5 and another embodiment of the present invention shown in FIG. In all cases.

On the other hand, as shown in Figures 2 to 5, the lens holder 20 is formed with a tuft 38 so as to be able to wind the tilt coil 37, the tilt coil 37 directly to the tuft 38 It is preferable to wind with.

2 to 5 are formed so that the tuft 38 is located on both sides of the objective lens 10 in the radial direction so as to drive the movable part of the actuator in the radial tilt direction by a pair of tilt coils 37. 38 shows an example in which the tilt coil 37 is wound.

The tufts 38 are located at both sides along the radial direction of the objective lens 10 of the upper portion of the lens holder 20, as shown in Figs. It is preferable that both portions are provided so as to be able to wind the tilt coil 37 so as to face the pair of single-pole magnetized magnets 31 and to be used as an effective coil. In this case, the tilt coil 37 is wound in parallel with the focus coil 33.

In this case, it is preferable that the pair of tilt coils 37 positioned on the upper portion of the lens holder 20 are wound in opposite directions. In this case, when the same current is applied to the pair of tilt coils 37, the directions in which the actual current flows in the pair of tilt coils 37 are opposite to each other, so that the direction of the current flowing through the tilt coil 37 and the single pole Considering the direction of the magnetic flux generated in the magnet magnet 31, the electromagnetic force in the vertical direction opposite to each other is generated according to the left hand law of the flaming, thereby moving the movable part in the tilt direction.

Therefore, when the coil 38 is formed as described above and the tilt coil 37 is wound thereon, the pair of single pole magnet magnets 31 and the pair of tilt coils 37 disposed on both sides of the objective lens 10 in the tangential direction. ), It is possible to stably drive the entire actuator moving part in the radial tilt direction.

Here, as described above, when the tuft 38 is formed on the upper portion of the lens holder 20, and the tilt coil 37 is positioned on the upper portion of the lens holder 20, the objective lens 10 is a lens holder ( Since it is installed in the upper portion of 20), the radial tilt driving center is located close to the objective lens 10, there is an advantage that can minimize the interference to the focus during the tilt driving.

The tufts 36 and 38 are formed in the lens holder 20 to enable the alignment winding, so that the focus coil 33, the tracking coil 35 and / or the tilt coil 37 are directly in the lens holder 20. In the case of winding, the tufts 36 and 38 also have an advantage of acting as a guide for suppressing coil deformation during inflow of overcurrent.

As described above, when the optical pickup actuator according to the embodiment of the present invention has the lens holder 20 and the magnetic circuit configuration as shown in FIGS. 2 to 5, two single-pole magnetized magnets 31, It becomes a triaxial drive actuator having a lens holder 20 capable of alignment winding, two tilt coils 37, one focus coil 33, and four tracking coils 35.

Referring to FIG. 7 schematically illustrating an optical pickup actuator according to another embodiment of the present invention, in the optical pickup actuator according to the present invention, a tuft 38 for winding the tilt coil 37 may have a lower side of the lens holder 20. It may be further formed on both sides along the radial direction of the objective lens 10 of the portion, and the tilt coil 37 may have a structure further wound on this tuft 38, respectively. That is, the optical pickup actuator according to the present invention may have a structure in which two tilt coils 37 are disposed in the radial direction, respectively, in the vertical direction.

In this case, to make the entire height of the optical pickup actuator the same as in the case of the embodiment of the present invention, the portion occupied by the focus coil 33 may be reduced.

As shown in FIG. 7, when a pair of tilt coils 37 for radial tilt driving are further provided on the lower portion of the lens holder 20, the radial tilt driving force may be increased.

The optical pickup actuator shown in FIG. 7 includes two single-pole magnetized magnets 31, a lens holder 20 arranged to enable alignment winding, four tilt coils 37, one focus coil 33 and four tracking coils. It is a three-axis drive actuator provided with 35.

On the other hand, as shown in Figures 2 to 7, the lens holder 20 is provided with an installation portion 25 for installing the objective lens 10 to protrude on the upper side, this installation portion 25 and the lens It is preferable that a predetermined gap g is formed between the pair of tufts 38 formed on the upper portion of the holder 20 and the tilt coil 37 wound thereon. As shown in FIG. 7, when the tilt coil 37 is also provided at the lower side of the lens holder 20, the objective lens 10 attaching portion 25 and the skein 38 at the lower portion of the lens holder 20 are provided. It is more preferable to form a gap g also between

As described above, when the tilt coil 37 and the mounting portion 25 are separated from each other so that the tilt coil 37 does not touch the mounting portion 25, it is generated by the current applied to the tilt coil 37 during tilt control. The influence of the heated heat on the objective lens 10 can be reduced, thereby protecting the objective lens from overcurrent. This is because when the space between the mounting portion 25 and the tilt coil 37 is separated, the heat pass can be lengthened and the heat transfer rate can be slowed down.

In addition, as shown in FIG. 8, at least one heat transfer blocking hole 27 is formed in the lens holder 20 in order to lengthen the heat path around the mounting portion 25. desirable. 8 shows an example in which a heat transfer blocking hole 27 is formed between the coil 38 for winding the tilt coil 37 and the installation portion 25 of the objective lens 10. The heat transfer blocking hole 27 may be applied to all of the cases of FIGS. 2, 6, and 7.

The heat transfer blocking hole 27 may be formed in the form of an open hole or a closed hole within the range in which the lens holder 20 has the required rigidity.

On the other hand, the optical pickup actuator according to the embodiments of the present invention as described above, as shown in Figures 2 and 4, a pair of outer yoke 15 and / or outer yoke formed in the base 11 It is preferable to further include a pair of inner yoke 17 formed in the base 11 so as to be located between the 15.

The unipolar magnet magnet 31 is mounted on the outer yoke 15. As shown in FIG. 4, the inner yoke may be located at an inner portion of the tilt coil 37 so that the inner yoke may be commonly applied to the focus coil 33, the tracking coil 35, and the tilt coil 37. .

In the above, the optical pickup actuator according to the present invention has been described and illustrated as having a configuration in which both the tracking coil 35 and the tilt coil 37 are directly wound on the lens holder 20, but the present invention is not limited thereto. . That is, the optical pickup actuator according to the present invention directly winds one of the tracking coil 35 and the tilt coil 37 to the lens holder 20, and the other part of the optical coil wound in advance to the lens holder 20. It may have a structure to attach.

In addition, the optical pickup actuator according to the present invention may have a structure in which the bulking coil wound around the tracking coil 35 and the tilt coil 37 is attached to the lens holder 20.

Even when the tilt coil 37 is attached to the lens holder 20, the tilt coil 37 is attached to the upper portion of the lens holder 20 to be spaced apart from the mounting portion 25, and the tilt coil 37 is generated in the tilt coil 37. It is desirable to be able to reduce the effect of the heat applied to the objective lens (10).

For the structure in which the lens holder 20 is formed without the tuft 36 and / or the tuft 38, and the tracking coil 35 and / or the tilt coil 37 are attached to the lens holder 20 Since it can fully infer from FIGS. 2-8, illustration is abbreviate | omitted.

As described above, the symmetric optical pickup actuator according to the exemplary embodiment of the present invention has a structure corresponding to a two-sided magnetic circuit. This is because the optical pickup actuator according to the present invention uses only two of four sides of the lens holder 20 to arrange the magnetic circuit. Here, the conventional optical pickup actuator described with reference to FIG. 1 uses all four sides of the lens holder 20 to arrange magnetic circuits.

In the above, the embodiments in which the magnetic circuit of the present invention is applied to a symmetrical actuator in which the objective lens center and the driving center coincide with each other are described and illustrated. The magnetic circuit of the present invention is applied to an asymmetrical actuator in which the objective lens center and the driving center do not coincide. May be applied.

9 is a perspective view showing another embodiment of the optical pickup actuator according to the present invention, asymmetric optical pickup actuator, Figure 10 is an exploded perspective view of FIG. FIG. 11 is a side view based on the line XI-XI of FIG. 9. FIG.

9 to 11, in the optical pickup actuator according to another exemplary embodiment of the present invention, an objective lens 10 is mounted on one side of the lens holder 50, and a pair of monopole magnets 31 are mounted on the objective lens. 10 is fixed to the base 51 so as to face each other on one side, the coil assembly 60 including a focus coil 33, a tracking coil 35 and a tilt coil 37 is the unipolar magnet 31 It is made of an asymmetrical structure that is mounted on the lens holder 50 so as to be located therebetween. 9 and 10, reference numeral 52 is provided on one side on the base 51, the holder is fixed to the suspension (13). As described above, the suspension 13 has one end coupled to the lens holder 50 and the other end fixed to the holder 52 to movably support the lens holder 50 with respect to the base 51.

Here, the members having substantially the same functions as in the previous embodiment are denoted by the same reference numerals, and repetitive description as possible will be omitted.

In the present embodiment, the coil assembly 60 includes a bobbin 61 on which the focus coil 33 is wound, and has a structure in which at least the focus coil 33 is aligned and wound around the bobbin 61.

FIG. 10 shows an example in which a tuft 66 for winding the tracking coil 35 and a tuft 68 for winding the tilt coil 37 are formed on the bobbin 61. The tuft 68 is formed on both sides of the bobbin 61 along the radial direction of the objective lens 10 of the upper and / or lower part, and the tilt coil 37 is wound around the tuft 68, respectively. 9 to 11, a tuft 68 is formed on both sides of the bobbin 61 along the radial direction of the objective lens 10, and a tilt coil 37 is wound around the tuft 68. Shows. A tuft 68 for winding the tilt coil 37 and a tilt coil 37 wound thereon may also be provided in the lower portion of the bobbin 61, as in FIG. 7.

As shown in FIG. 10, when the tufts 66 and 68 for winding the tracking coil 35 and the tilt coil 37 are formed on the bobbin 61, not only the focus coil 33 but also the tracking coil ( 35) and the tilt coil 37 can also be aligned winding.

2 and 3 and 10, in the coil assembly 60, the bobbin 61, the projection jaw 23 and the objective lens 10 for installing the suspension 13, Excluding the mounting portion 25 for installation has a structure substantially the same as that of the lens holder 20 in the previous embodiment, and the relative arrangement between the focus coil 33, the tracking coil 35, and the tilt coil 37. The relationship is also substantially the same as in the previous embodiment.

Here, the coil assembly 60 has been described and illustrated as having a configuration in which the tracking coil 35 and the tilt coil 37 are wound directly on the bobbin 61, and the coil assembly 60 includes the tracking coil 35. ) And the tilt coil 37 may be wound directly on the bobbin 61, and the other may have a structure in which a pre-wound bulk coil is attached to the bobbin 61.

In addition, the coil assembly 60 may be configured to attach to the bobbin 61 using a bulk coil, which is prewound with both the tracking coil 35 and the tilt coil 37.

Meanwhile, referring to FIGS. 10, 12, and 13, the optical pickup actuator according to another embodiment of the present invention may further include a top cover 70 or 170 to guide the magnetic flux.

As shown in FIG. 12, the top cover 70 includes a bridge 71 positioned above the magnetic circuit, a pair of outer yokes 73 extending from the bridge 71, and a pair of inner yokes 75. It may be configured to include). A single pole magnet magnet 31 is installed inside each of the outer yoke 73, and both ends thereof may be coupled to the base 51. The inner yoke 75 is formed to be disposed inside the tilt coil 37, and penetrates the inside of the tilt coil 37 to be coupled to the base 51.

Alternatively, as shown in FIG. 13, the top cover 170 includes a bridge 171 and an inner yoke 175 and may be configured to have a partial outer yoke 173. In this case, a partial outer yoke 174 coupled to the partial outer yoke 173 is provided in the base 151 so that the partial outer yoke 174 supports the unipolar magnetizing magnet 31, When the inner yoke 175 of the top cover 170 is coupled to the base 151, the partial outer yoke 173 extending from the bridge 171 of the top cover 170 is a partial outer yaw of the base 151. The monopole magnetized magnet 31 is supported while being engaged with the oak 174.

In addition, the structure of the top cover may be modified in various ways. That is, the top cover may have a configuration including only the bridge and the inner yoke. In this case, the outer yoke for mounting the monopole magnetized magnet 31 is formed in the base.

As another example, the inner yoke may be provided in the base, and the outer yoke in which the bridge and the single pole magnet 31 are fixed to the top cover may be provided and coupled to the base.

Regardless of the configuration in any of the above cases, a very effective control sensitivity can be obtained with the coil assembly 60 disposed in a limited narrow space between the pair of single pole magnet magnets 31.

On the other hand, in the optical pickup actuator according to another embodiment of the present invention, instead of having the top cover as described above, as shown in Figure 14, both the outer yoke 273 and the inner yoke 275 as a base ( 251 may be formed.

FIG. 15 is an exploded perspective view showing an optical pickup actuator according to another embodiment of the present invention. Compared with FIG. 10, the coil assembly 160 is obtained by attaching coils of a pre-wound bulk type to each other. It is characterized by the fact that bobbins are excluded. In FIG. 15, the rest of the configuration except for the coil assembly 160 is illustrated as the same as FIG. 10, but is not limited thereto. As in the foregoing embodiment, various modifications of the top cover and / or the base structure are possible. Here, the members having substantially the same functions as in the previous embodiment are denoted by the same reference numerals and description thereof is omitted where possible.

As shown in FIG. 15, the coil assembly 160 includes a bulk coil in which the focus coil 133, the tracking coil 135, and the tilt coil 137 are all wound in advance, and the focus coil 133 is provided. The tracking coil 135 and the tilt coil 137 may be attached to. At this time, the arrangement structure of the focus coil 133, the tracking coil 135, and the tilt coil 137 and its function include the focus coil 33, the tracking coil 35, and the tilt coil 37 in FIG. 10. It is substantially the same as in the case of the coil assembly 60.

16 is an exploded perspective view of an asymmetric optical pickup actuator according to another embodiment of the present invention, in which the coil assembly 260 is disposed in a direction crossing with a direction in which a pair of single pole magnet magnets 31 are disposed. And a plurality of focusing coils 233a and 233b, and a plurality of tracking coils 235 positioned on at least one side of the pair of focusing coils 233a and 233b facing the single-pole magnet magnet 31. The feature is that the tilt coil is excluded from the structure.

In FIG. 16, as in the case of FIG. 15, the coil assembly 260 may have a structure in which the alignment winding bobbin is distributed. That is, the coil assembly 260 is made of a bulk type coil in which the focus coils 233a and 233b and the tracking coil 235 are all wound in advance, and the pair of focus coils 233a and 233b are attached to each other. The tracking coil 235 may be attached to the focus coils 233a and 233b.

At this time, the pair of inner yoke 75 provided on the top cover 70 is disposed inside the focus coils 233a and 233b, respectively.

In FIG. 16, the rest of the configuration except for the coil assembly 260 is illustrated as the same as in FIG. 10, but is not limited thereto. As in the foregoing embodiment, various modifications of the top cover and / or the base structure are possible. Here, the members having substantially the same functions as in the previous embodiment are denoted by the same reference numerals and description thereof is omitted where possible.

17 is a diagram schematically showing the configuration of an optical recording and / or reproducing apparatus employing the optical pickup actuator according to the present invention.

Referring to FIG. 17, an optical recording and / or reproducing apparatus includes a spindle motor 355 for rotating an optical information storage medium, for example, an optical disk D, and a movable optical disk in a radial direction of the optical disk D. The optical pickup 350 for reproducing and / or recording the information recorded in the data, the driver 357 for driving the spindle motor 355 and the optical pickup 350, and the focus and tracking of the optical pickup 350. And a control unit 370 for controlling the tilt servo. Here, reference numeral 352 denotes a turntable, and 353 denotes a clamp for chucking the optical disk D. FIG.

The optical pickup 350 includes an optical pickup optical system including an objective lens 10 for focusing light emitted from a light source onto the optical disc D, and an optical pickup actuator for driving the objective lens 10 in three axes. . At this time, any one of the optical pickup actuator according to various embodiments of the present invention as described above may be applied to the optical pickup actuator.

The light reflected from the optical disc D is detected through a photodetector provided in the optical pickup 350, photoelectrically converted into an electrical signal, and the electrical signal is input to the controller 359 through the driver 357. The driver 357 controls the rotational speed of the spindle motor 355, amplifies the input signal, and drives the optical pickup 350. The control unit 359 sends the focus servo, tracking servo, and tilt servo commands adjusted based on the signal input from the driving unit 357 to the driving unit 357 again, so that the focusing, tracking, and tilting operations of the optical pickup 350 are performed. To be implemented.

As described above, the optical pickup actuator according to the present invention is capable of both symmetrical and asymmetrical types, and uses a single pole magnet, and enables three-axis driving by limiting the number of single pole magnets to two, thereby reducing material costs. It can be applied to slim, slim and thicker shapes. The material cost is reduced because two low-cost, single-pole magnets are used to construct the magnetic circuit.

In addition, when winding at least some coils directly to the lens holder or bobbin, product dispersion is reduced to reduce the defective rate.

In addition, the optical pickup actuator according to the present invention is guaranteed linearity. The linearity decreases as more polarizations are applied to the same plane, because the magnetic flux density in the neutral zone between the polarization and the polarization is zero, so the closer to this area the magnetic flux density is in the transition zone. This is because the total force of Lorentz force changes. Since the optical pickup actuator according to the present invention uses a single-pole magnetized magnet, the linear pickup actuator is excellent in linearity.

In addition, according to the symmetrical optical pickup actuator according to the present invention, the objective lens can be protected against overcurrent by forming at least one heat transfer blocking hole in the gap and / or lens holder between the objective lens mounting portion and the skein of the lens holder. have.

1 is a plan view schematically showing an example of a conventional optical pickup actuator;

2 is a perspective view schematically showing an optical pickup actuator according to an embodiment of the present invention;

3 is a perspective view showing only the lens holder of Figure 2,

4 is a plan view of FIG.

5 is a cross-sectional view taken along the line A-A of FIG.

FIG. 6 is a diagram illustrating another example of a magnetic circuit of the optical pickup actuator according to an embodiment of the present disclosure, corresponding to FIG. 5;

7 is a view illustrating another example of a magnetic circuit of the optical pickup actuator according to an embodiment of the present invention, corresponding to FIG. 5;

8 is a view showing another example of a lens holder in an optical pickup actuator according to an embodiment of the present invention;

9 is a perspective view showing an asymmetric optical pickup actuator as another embodiment of the optical pickup actuator according to the present invention;

10 is an exploded perspective view of FIG. 9;

FIG. 11 is a side view based on the line VII-XI of FIG. 9; FIG.

12 is an exploded perspective view illustrating the top cover and the base of FIG. 9;

13 is an exploded perspective view showing another example of a top cover and a base in an optical pickup actuator according to another embodiment of the present invention;

14 is a perspective view illustrating still another example of a base in an optical pickup actuator according to another embodiment of the present invention;

15 is an exploded perspective view showing an asymmetric optical pickup actuator according to another embodiment of the present invention;

16 is an exploded perspective view showing an asymmetric optical pickup actuator according to another embodiment of the present invention;

FIG. 17 is a diagram schematically showing the configuration of an optical recording and / or reproducing apparatus employing an optical pickup actuator according to the present invention. FIG.

<Description of the symbols for the main parts of the drawings>

10 ... objective lens 11,51,151,251 ... base

13.Suspension 15,73,173,174,273 ... outer yoke

17,75,175,275 Inner yoke 20,50 Lens holder

25.Mounting section 27 ... Heat transfer blocking hole

31.Single pole magnet 33,133,233a, 233b ... Focus coil

35,135,235 ... Tracking Coil 36,38,66,68 ...

37,137 ... Tilt coil 60,160,260 ... Coil assembly

70 ... Top Cover 71 ... Bridge

g ... hole

Claims (33)

A lens holder mounted with an objective lens and movably supported with respect to the base by suspension; In the optical pickup actuator comprising a; magnetic circuit for driving the objective lens, The magnetic circuit, A pair of unipolar magnetizing magnets fixed to the base to face each other; A focus coil mounted to the lens holder to be positioned between the pair of single pole magnets; A plurality of tracking coils located on a side of the focus coil facing the single pole magnet; And a plurality of tilt coils positioned above and / or below the focus coil when the central axis direction of the objective lens is referred to as an up and down direction. The pair of unipolar magnets are fixed to the base so as to face opposite sides of the lens holder, the focus coil is wound around the lens holder, and the tracking coil is the lens facing the unipolar magnets. Installed on the side of the holder, the tilt coil is a symmetrical structure installed on the upper and / or lower portion of the lens holder, The lens holder is provided with an installation portion for installing the objective lens spaced apart from the tilt coil disposed in the upper portion of the lens holder, it is possible to reduce the effect of heat on the objective lens Actuator. delete The method of claim 1, wherein a plurality of tufts are formed to wind the tracking coil on the lens holder, and the tracking coil is wound on the tuft or the tracking coil is attached to the lens holder. Optical Pickup Actuator. The lens holder of claim 1, wherein a skein is formed on both sides of the lens holder in a radial direction of an objective lens of an upper side and / or a lower side of the lens holder, and the tilt coil is formed on a pair of upper side and / or lower side of the lens holder. Optical pickup actuators, characterized in that each wound on the skein. delete 5. The heat transfer blocking device of claim 1, wherein the lens holder is configured to reduce heat transfer from the focus coil, the tracking coil, and / or the tilt coil to the objective lens. An optical pickup actuator, characterized in that at least one hole is formed. A lens holder mounted with an objective lens and movably supported with respect to the base by suspension; In the optical pickup actuator comprising a; magnetic circuit for driving the objective lens, The magnetic circuit, A pair of unipolar magnetizing magnets fixed to the base to face each other; A focus coil mounted to the lens holder to be positioned between the pair of single pole magnets; A plurality of tracking coils located on a side of the focus coil facing the single pole magnet; And a plurality of tilt coils positioned above and / or below the focus coil when the central axis direction of the objective lens is referred to as an up and down direction. The objective lens is mounted on one side of the lens holder, the pair of monopole magnets are fixed to the base to face each other on one side of the objective lens, A coil assembly including the focus coil, the tracking coil, and the tilt coil is mounted on the other side of the lens holder such that the coil assembly is positioned between the pair of unipolar magnets, The coil assembly further includes a bobbin in which at least the focus coil is aligned and wound; Skeins are formed on both sides of the bobbin along the radial direction of the objective lens of the upper and / or lower part, and the tilt coil is wound around a pair of tufts formed on the upper and / or lower part of the bobbin, respectively. Optical pickup actuator. delete The optical pickup actuator of claim 7, wherein a bobbin is formed on the bobbin to wind the tracking coil, and the tracking coil is wound on a bobbin formed on the bobbin. delete A lens holder mounted with an objective lens and movably supported with respect to the base by suspension; In the optical pickup actuator comprising a; magnetic circuit for driving the objective lens, The magnetic circuit, A pair of unipolar magnetizing magnets fixed to the base to face each other; A focus coil mounted to the lens holder to be positioned between the pair of single pole magnets; A plurality of tracking coils located on a side of the focus coil facing the single pole magnet; And a plurality of tilt coils positioned above and / or below the focus coil when the central axis direction of the objective lens is referred to as an up and down direction. The objective lens is mounted on one side of the lens holder, the pair of monopole magnets are fixed to the base to face each other on one side of the objective lens, A coil assembly including the focus coil, the tracking coil, and the tilt coil is mounted on the other side of the lens holder such that the coil assembly is positioned between the pair of unipolar magnets, The coil assembly has a structure in which the bulk coil, which is pre-wound with the focus coil, the tracking coil, and the tilt coil, is attached to the focus coil, and the tracking coil and the tilt coil are attached to the focus coil. 12. The optical pickup actuator of any one of claims 7, 9 and 11, further comprising a bridge positioned above the magnetic circuit to guide the magnetic flux. A pair of outer yokes extending from said bridge and supporting said pair of unipolar magnet magnets and / or a pair of inner yokes extending from said bridge and disposed inside a tilt coil of said coil assembly. Optical pickup actuators further comprising; 12. The pair of outer yokes according to any one of claims 1, 3, 4, 7, 9, or 11, which are formed in the base and on which the single-pole magnet is mounted. /or; And a pair of inner yokes formed in the base so as to be positioned inside the tilt coil. The method of claim 1, wherein the tracking coil is located closer to the unipolar magnet magnet than the focus coil or the focus coil. An optical pickup actuator, characterized in that it is located closer to the unipolar magnet magnet than the tracking coil. delete delete An optical pickup having an actuator for driving an objective lens, the optical pickup being removably installed in the radial direction of the optical information storage medium for reproducing or recording information recorded on the optical information storage medium; An optical recording and / or reproducing apparatus, comprising: a control unit for controlling focus, track, and tilt servos; The actuator is A lens holder mounted with an objective lens and movably supported with respect to the base by suspension; A pair of single pole magnets fixed to the base to face each other, a focus coil installed on the lens holder to be positioned between the pair of single pole magnets, and a side of the focus coil facing the single pole magnet A magnetic circuit including a plurality of tracking coils and a plurality of tilt coils positioned above and / or below the focus coil when the direction of the center axis of the objective lens is a vertical direction; Including; The pair of unipolar magnets are fixed to the base so as to face opposite sides of the lens holder, the focus coil is wound around the lens holder, and the tracking coil is the lens facing the unipolar magnets. Installed on the side of the holder, the tilt coil is a symmetrical structure installed on the upper and / or lower portion of the lens holder, Skeins are formed on both sides of the lens holder along the radial direction of the upper and / or lower part of the lens holder, and the tilt coil is wound around a pair of tufts formed on the upper and / or lower part of the lens holder, respectively. Optical recording and / or reproducing apparatus. delete 19. The method of claim 18, wherein a plurality of tufts are formed to wind the tracking coil to the lens holder, and the tracking coil is wound on the tuft or the tracking coil is attached to the lens holder. Optical recording and / or reproducing apparatus. delete 21. The method of claim 18 or 20, wherein the lens holder is formed with at least one heat transfer blocking hole is formed in order to reduce the transfer of heat generated from the focus coil, tracking coil and / or tilt coil to the objective lens And an optical recording and / or reproducing apparatus. An optical pickup having an actuator for driving an objective lens, the optical pickup being removably installed in the radial direction of the optical information storage medium for reproducing or recording information recorded on the optical information storage medium; An optical recording and / or reproducing apparatus, comprising: a control unit for controlling focus, track, and tilt servos; The actuator is A lens holder mounted with an objective lens and movably supported with respect to the base by suspension; A pair of single pole magnets fixed to the base to face each other, a focus coil installed on the lens holder to be positioned between the pair of single pole magnets, and a side of the focus coil facing the single pole magnet A magnetic circuit including a plurality of tracking coils and a plurality of tilt coils positioned above and / or below the focus coil when the direction of the center axis of the objective lens is a vertical direction; Including; The objective lens is mounted on one side of the lens holder, the pair of monopole magnets are fixed to the base to face each other on one side of the objective lens, A coil assembly including the focus coil, the tracking coil, and the tilt coil is mounted on the other side of the lens holder such that the coil assembly is positioned between the pair of unipolar magnets, The coil assembly further includes a bobbin in which at least the focus coil is aligned and wound; Skeins are formed on both sides of the bobbin along the radial direction of the objective lens of the upper and / or lower part, and the tilt coil is wound around a pair of tufts formed on the upper and / or lower part of the bobbin, respectively. Optical recording and / or reproducing apparatus. delete 24. The optical recording and / or reproducing apparatus according to claim 23, wherein a bobbin is formed on the bobbin to wind the tracking coil, and the tracking coil is wound on a tuft formed on the bobbin. delete An optical pickup having an actuator for driving an objective lens, the optical pickup being removably installed in the radial direction of the optical information storage medium for reproducing or recording information recorded on the optical information storage medium; An optical recording and / or reproducing apparatus, comprising: a control unit for controlling focus, track, and tilt servos; The actuator is A lens holder mounted with an objective lens and movably supported with respect to the base by suspension; A pair of single pole magnets fixed to the base to face each other, a focus coil installed on the lens holder to be positioned between the pair of single pole magnets, and a side of the focus coil facing the single pole magnet A magnetic circuit including a plurality of tracking coils and a plurality of tilt coils positioned above and / or below the focus coil when the direction of the center axis of the objective lens is a vertical direction; Including; The objective lens is mounted on one side of the lens holder, the pair of monopole magnets are fixed to the base to face each other on one side of the objective lens, A coil assembly including the focus coil, the tracking coil, and the tilt coil is mounted on the other side of the lens holder such that the coil assembly is positioned between the pair of unipolar magnets, The coil assembly has a structure in which a bulk coil pre-wound with the focus coil, the tracking coil and the tilt coil is used, and the tracking coil and the tilt coil are attached to the focus coil. . 28. The optical recording and / or reproducing apparatus as claimed in any one of claims 23, 25 or 27, further comprising a bridge located above the magnetic circuit to guide the magnetic flux. 29. The pair of inner yokes of claim 28, extending from the bridge and supporting the pair of monopole magnets and / or extending from the bridge and disposed inside the tilt coil of the coil assembly. And an optical recording and / or reproducing apparatus further comprising. The method according to any one of claims 18, 20, 23, 25 or 27, A pair of outer yokes formed in the base and on which the monopole magnet is mounted; And a pair of inner yokes formed in the base so as to be positioned inside the tilt coil. 28. The tracking coil of claim 18, 20, 23, 25, or 27, wherein the tracking coil is located closer to the unipolar magnet magnet than the focus coil, or the focus coil is the tracking coil. An optical recording and / or reproducing apparatus, characterized in that it is located closer to the unipolar magnet magnet. delete delete