KR20010112774A - Lens actuator for pick-up - Google Patents

Abstract

The invention relates to novel desoxycyclodepsipeptides of formula (I) in which C=X 1, C=X 2, C=X 3 and C=X 4 independently of each other respectively represent one of the CO, CS or CH 2 groups, with at least one of these groups representing CH 2. The invention also relates to their mixtures and derivatives. Said compounds are produced from cyclodepsipeptides having 24 ring members formed by alternating alpha-amino carboxylic acids and alpha- hydroxy carboxylic acids by complete or partial chemoselective reduction of the carbonyl groups of the amide function into methylene groups, using suitable reduction methods. The desoxycyclodepsipeptides produced according to the invention have an anthelmintic effect.

Description

Lens actuator for optical pickup {LENS ACTUATOR FOR PICK-UP}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens actuator for optical pickup, and more particularly, to an optical pickup lens actuator having a structure capable of miniaturizing the actuator in both the vertical and horizontal directions so as to be applied to a slim CD-ROM or a slim DVROM mainly used in a notebook computer. It is about.

In general, an optical disc information storage device such as a CD or a DVD reads information input to the disc by irradiating a laser beam onto the disc. The laser beam should be irradiated correctly.

In other words, when the laser beam is directed toward the disc, a predetermined positional accuracy must be secured in the tracking direction and the focusing direction of the laser beam.

As described above, the VCM (Voice Coil Motor) actuator is applied to the optical pickup for emitting the laser beam to secure the positional accuracy of the laser beam, thereby actively positioning the objective lens in the two axis directions, that is, the tracking direction and the focusing direction. To control.

In this case, the actuator is formed to have a small rigidity so that a relatively large displacement can be made even with a small driving current.

There are several kinds of such actuators, and among them, rotary lens type actuators are frequently used.

In the case of an optical pickup including two light sources having different wavelengths and two objective lenses having different numerical apertures, the lens switching function selects and positions a specific objective lens on the actuator in the optical axis. This should be provided because it is the easiest to implement such a lens switching function in a rotary lens type actuator.

The rotary lens actuator as described above has a structure in which two objective lenses are assembled to form a predetermined angle on the lens holder, and a coil for generating a driving force is mounted on the side of the lens holder. In addition, a permanent magnet is installed in the base for supporting the lens holder so as to correspond to the coil, and a rotating shaft for guiding the central axis of the lens holder is assembled in the vertical direction.

In addition, the lens holder is fitted to the rotation axis of the base so as to be slidable in the axial and circumferential direction, that is, the focusing direction and the tracking direction, and the lens holder in the center position of the coil of the lens holder is predetermined in the axial direction and the circumferential direction The iron piece is assembled to have a restoring force so that the lens holder can have a magnetic stiffness in the magnetic field formed by the permanent magnet of the base through the iron piece.

Hereinafter, a conventional rotary lens type actuator will be described in detail using an optical pickup device disclosed in Japanese Patent Application No. 8-44974.

First, a rotation shaft 5 is integrally formed at the center of the base 3 for supporting the cylindrical lens holder 1, and the lens holder 1 can be driven in the focus direction and the tracking direction on the rotation shaft 5. To be combined. That is, the lens holder 1 is installed to be able to vertically move along the rotation shaft 5 and to be rotatable about the rotation shaft 5.

In addition, the first objective lens 7A and the second objective lens 7B formed to have different numerical apertures are assembled on the upper surface of the lens holder 1 to form a predetermined angle with each other.

In addition, on the outer circumferential surface of the lens holder 1, a focusing coil 9 and a tracking coil 11 for moving the first objective lens 7A and the second objective lens 7B in the focusing direction and the tracking direction are provided. It is installed.

Here, the focusing coil 9 is installed in a form wound on the outer circumferential surface of the lens holder 1, and the tracking coil 11 is provided with a predetermined interval along the circumference of the lens holder 1. It is installed.

In addition, the tracking coils 11 are arranged in pairs so that each pair is positioned to face each other, and a first for driving the first objective lens 7A and the second objective lens 7B, respectively. It is divided into a tracking coil and a second tracking coil.

In addition, the base 3 is provided with six permanent magnets 13A, 13B, 15A, 15B, 17A, and 17B so that the focusing coil 9 and the tracking coil 11 are positioned in the magnetic field. Each of the permanent magnets 13A, 13B, 15A, 15B, 17A, and 17B is mounted to a yoke portion 3 'protruded upward from the edge of the base 3 to provide the focusing coil ( 9) and the tracking coil 11.

That is, each of the permanent magnets 13A, 13B, 15A, 15B, 17A, and 17B is mounted on the inner side of the yoke portion 3 'of the base 3 so that the circumferential direction of the lens holder 1 can be achieved. It is installed to be located outside of the furnace.

In addition, each of the permanent magnets 13A, 13B, 15A, 15B, 17A, and 17B is arranged in pairs so that each pair is positioned to face each other, and the focusing coil 9 and Together, a pair of focusing permanent magnets 13A and 13B for generating a movable force in the focusing direction and two pairs of permanent magnets for tracking 15A for generating a movable force in the tracking direction together with the tracking coil 11. 15B, 17A, and 17B.

That is, when a current flows through the focusing coil 9, the first objective lens 7A and the second objective lens 7B are moved in the focusing direction by the magnetic field of the focusing permanent magnets 13A and 13B. A Lorentz force in the axial direction is generated, and when a current flows through the tracking coil 11, the first objective lens is driven by a magnetic field by the permanent magnets 15A, 15B, 17A, and 17B for tracking. The Lorentz force in the circumferential direction is generated for moving the 7A) and the second objective lens 7B in the tracking direction.

At this time, the tracking coil 11 and the tracking permanent magnets 15A, 15B, 17A, and 17B may move the first objective lens 7A and the second objective lens 7B in the tracking direction. The function of switching the positions of the first objective lens 7A and the second objective lens 7B is also performed.

Finally, the lens holder 1 is equipped with iron pieces (not shown) for generating magnetic stiffness in the focusing direction and the tracking direction therein, through the focusing coil 9 and the tracking coil 11. When the forced electromagnetic force is removed, it can return to the original position.

However, such a conventional optical pickup lens actuator has six permanent magnets 13A, 13B, 15A, 15B and 17A for positioning the focusing coil 9 and the tracking coil 11 in a magnetic field. Since both 17B are provided on the outer side in the circumferential direction of the lens holder 1, the occupied space is relatively large not only in the vertical direction but also in the horizontal direction, thereby increasing the space limitation.

Such a space problem is further exacerbated in the case of a slim CD-ROM or DVD-ROM, which is mainly employed in a notebook computer, and thus the conventional optical pickup lens actuator is hardly available for the slim CD-ROM or DVD-ROM.

In other words, in general, a spindle motor for rotating a disk needs a certain space between the stator and the rotor to generate the required torque. In particular, in the case of a slim CD-ROM or DVD-ROM, a thin rotor is required due to the limitation in the thickness direction. Since it is necessary to employ a large diameter, it is inevitable to employ a large-diameter rotor in the radial direction.

Accordingly, the space in the horizontal direction occupied by the spindle motor in the slim CD-ROM or DVD-ROM is increased. In the conventional optical pickup lens actuator, since the space occupied in the horizontal direction is relatively large, spatial interference with the spindle motor is reduced. It becomes severe and becomes difficult to apply to a slim cdrom or dibrom.

The object of the present invention devised in view of the above problems is to have a structure capable of miniaturizing the actuator in both the vertical and horizontal directions so that two objective lenses must be provided while being spatially narrow like a slim CD-ROM or a DI-ROM. An object of the present invention is to provide a lens actuator for an optical pickup that can be applied to an optical pickup.

1 is a perspective view showing a lens actuator for an optical pickup according to the prior art,

2 is an exploded perspective view showing an optical pickup lens actuator according to the present invention;

3 is a perspective view showing the structure of a lens holder according to the present invention.

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

51A: First Objective Lens 51B: Second Objective Lens

53 lens holder 53a holder plate

53b: insert 53c: support

55: base 55a: base plate portion

55b: yoke portion 56: rotating shaft

57: focusing coil 59A, 59B: focusing permanent magnet

61A, 61B: first tracking coil 63A, 63B: second tracking coil

65A, 65B: permanent magnet for tracking 67: iron piece

In order to achieve the object of the present invention as described above, in the lens actuator for the optical pickup coupled to the base so that the lens holder with n objective lenses having different numerical apertures is movable in the focusing direction and the tracking direction, Focusing lens driving means for driving the lens holder in the vertical direction is provided inside the lens holder in the radial direction so as to move the objective lens in the focusing direction, and the objective lens is located outside the lens holder in the radial direction. An optical pickup lens actuator is provided, characterized in that a tracking lens driving means for driving a lens holder in a circumferential direction to be movable in a tracking direction is provided.

In addition, an additional feature of the present invention is that the base consists of a base plate portion integrally formed with a rotating shaft to which the lens holder is coupled, and a yoke portion protruding upwardly at the edge of the base plate portion, and the lens holder includes: It is composed of a disc-shaped holder plate portion mounted on the upper surface, an insertion portion formed on the lower surface of the holder plate portion so that the rotary shaft is fitted and coupled, and a support portion protruding downward on the edge of the holder plate portion.

In addition, the focusing lens driving means is a focusing coil installed on the outer peripheral surface of the insertion portion of the lens holder, and is mounted on the upper surface of the base plate portion of the base to be located around the focusing coil It consists of two permanent magnets for focusing.

Further, an additional feature of the present invention is that the tracking lens driving means includes 2n tracking coils installed on the outer surface of the support of the lens holder, and 2 mounted on the inner surface of the yoke portion of the base so as to correspond to the tracking coils. It consists of two permanent magnets for tracking.

In addition, an additional feature of the present invention is that the tracking coils are arranged in pairs so that each pair is positioned to face each other, and the focusing permanent magnets and the tracking permanent magnets are disposed to face each other. Are also placed at intervals.

In addition, an additional feature of the present invention is that, on the support portion of the lens holder, iron pieces for generating magnetic stiffness in the focusing direction and the tracking direction are mounted at the same positions as the tracking coils, respectively.

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

2 is an exploded perspective view showing an optical pickup lens actuator according to the present invention, Figure 3 is a perspective view showing the structure of the lens holder according to the present invention.

2 and 3, the optical actuator according to the present invention includes a base (not shown) so that the lens holder 53 having two objective lenses 51A and 51B is operated in a focusing direction and a tracking direction. 55, a lens driving lens for focusing to drive the lens holder 53 in the vertical direction so that the objective lens 51A, 51B is moved in the focusing direction on the inner side of the lens holder 53 in the radial direction. Means are provided, and tracking lens driving means for driving the lens holder 53 in the circumferential direction so that the objective lens 51A, 51B is movable in the tracking direction on the outer side of the lens holder 53 in the radial direction. Is installed.

Here, the first and second objective lenses 51A and 51B are formed to have different numerical apertures and are assembled to form a predetermined angle on the lens holder 53.

In addition, the base 55 includes a base plate portion 55a having an integrally formed rotary shaft 56 to which the lens holder 53 is coupled, and a yoke portion 55b protruding upward from an edge of the base plate portion 55a. Is made of.

In addition, the lens holder 53 is a holder plate portion 53a of a disc-shaped holder plate portion 53a having respective objective lenses 51A and 51B mounted on an upper surface thereof, and the holder plate portion 53a such that the rotation shaft 56 is fitted thereto. The insertion portion 53b formed on the lower surface of the support plate 53a is formed to protrude downwards at the edge of the holder plate portion 53a.

In addition, the focusing lens driving means includes a focusing coil 57 provided on an outer circumferential surface of the inserting portion 53b of the lens holder 53 and a base of the base 55 so as to be positioned around the focusing coil 57. It consists of two focusing permanent magnets 59A and 59B mounted on the upper surface of the plate portion 55a.

In addition, the tracking lens driving means includes four tracking coils 61A, 61B, 63A, 63B provided on the outer surface of the support portion 53c of the lens holder 53, and the tracking coil 61A ( It consists of two tracking permanent magnets 65A and 65B mounted on the inner surface of the yoke portion 55b of the base 55 so as to correspond to 61B) 63A and 63B.

In addition, the tracking coils 61A, 61B, 63A, and 63B are arranged in pairs so that each pair is positioned to face each other, and the support 53c of the lens holder 53 is for tracking. It is formed only in the position where the coil 61A, 61B, 63A, 63B is provided.

In addition, the tracking coils 61A, 61B, 63A, 63B include a first tracking coil 61A, 61B for driving the first objective lens 51A, and a second objective lens 51B. The second tracking coils 63A and 63B for driving the first tracking coils 61A and 61B and the second tracking coils 63A and 63B are electrically connected in series. Separate independent operations are possible.

In addition, the focusing permanent magnets 59A and 59B and the tracking permanent magnets 65A and 65B are disposed at 180 degree intervals so as to face each other.

In the support portion 53c of the lens holder 53, an iron piece 67 for generating magnetic stiffness in the focusing direction and the tracking direction is the same as the tracking coils 61A, 61B, 63A, 63B. Each mounted in position.

That is, the iron piece 67 is assembled at the same position as the tracking coils 61A, 61B, 63A, 63B, and placed in a position facing the tracking permanent magnets 65A, 65B. It serves to generate magnetic stiffness in the tracking direction.

Finally, the tracking lens driving means rotates the lens holder 53 to select the objective lenses 51A and 51B used for the disc reproducing / recording operation, so that the objective lenses 51A and 51B are rotated. Lens switching function to switch the position of also plays a role.

The optical actuator for optical pickup according to the present invention configured as described above operates as follows.

First, if the first objective lens 51A is used as an initial objective lens for recording / reproducing a disc, a current is applied to the focusing coil 57 to move the first objective lens 51A in the focusing direction. Shed.

In this way, when the current is supplied to the focusing coil 57, an electromagnetic force, that is, Lorentz force, is intended to drive the lens holder 53 in the focusing direction between the focusing coil 57 and the focusing permanent magnets 59A and 59B. (Lorentz Force) is generated.

When the Lorentz force is generated by passing a current through the focusing coil 57 in the magnetic field by the focusing permanent magnets 59A and 59B as described above, the lens holder 53 is rotated by the Lorentz force. The first objective lens 51A is driven in the focusing direction, that is, in the vertical direction.

At this time, the driving direction of the lens holder 53 is determined by the winding direction of the focusing coil 57 and the magnetization direction of the focusing permanent magnets 59A and 59B.

Similarly, when a current flows through the first tracking coils 61A and 61B to move the first objective lens 51A in the tracking direction, the first tracking coils 61A and 61B and the permanent magnet for tracking are performed. A Lorentz force for driving the lens holder 53 in the tracking direction is generated between 65A and 65B, and when the lens holder 53 is driven in the tracking direction by the electromagnetic force generated in this way, that is, the lens holder ( When 53 is rotated in the circumferential direction with respect to the rotation shaft 56, the first objective lens 51A is movable in the tracking direction.

In order to use the second objective lens 51B instead of the first objective lens 51A, the tracking coils 61A, 61B, 63A, 63B and the tracking permanent magnets 65A, 65B are used. The positions of the objective lenses 51A and 51B may be switched by using the tracking lens driving means.

Thereafter, when the positions of the respective objective lenses 51A and 51B are switched by the tracking lens driving means, that is, the second objective lens 51B can be used instead of the first objective lens 51A. The second objective lens 51B is operated in the focusing direction and the tracking direction in the same manner as the one objective lens 51A is operated to perform the recording / reproducing operation of the disc.

As described above, in the optical pickup lens actuator according to the present invention, the focusing coil 57 and the focusing permanent magnets 59A and 59B are provided inside the lens holder 53 in the radial direction. Since only two tracking permanent magnets 65A and 65B can be installed on the outer side of the holder 53 in the radial direction, the occupied space in the vertical direction as well as the horizontal direction can be reduced.

In particular, the present invention has an advantage in that the actuator can be miniaturized in both the vertical and horizontal directions, and thus it can be applied to an optical pickup that must have two objective lenses while being spatially narrow, such as a slim CD-ROM or DVD-ROM.

Claims (7)

In the lens actuator for optical pickup coupled to the base such that the lens holder having n objective lenses having different numerical apertures is movable in the focusing direction and the tracking direction, Lens driving means for focusing is provided inside the lens holder in the radial direction to drive the lens holder in the vertical direction so that the objective lens is moved in the focusing direction. An optical pickup lens actuator, characterized in that a tracking lens driving means for driving the lens holder in the circumferential direction is installed on the outer side of the lens holder in the radial direction. According to claim 1, wherein the base is composed of a base plate portion integrally formed with a rotating shaft to which the lens holder is coupled, and a yoke portion protruding upward on the edge of the base plate portion, The lens holder is composed of a disc-shaped holder plate portion on which each objective lens is mounted on an upper surface, an insertion portion formed on a lower surface of the holder plate portion so that the rotary shaft is fitted and coupled thereto, and a support portion protruding downwardly on an edge of the holder plate portion. Lens actuator for optical pickup, characterized in that. 3. The focusing lens driving means according to claim 2, wherein the focusing lens driving means comprises: a focusing coil installed on an outer circumferential surface of the insertion part of the lens holder, and two focusing permanent parts mounted on an upper surface of the base plate part of the base so as to be positioned around the focusing coil. Lens actuator for optical pickup, characterized in that consisting of a magnet. 3. The tracking lens driving means according to claim 2, wherein the tracking lens driving means includes 2n tracking coils provided on the outer side of the support of the lens holder, and two tracking permanentities mounted on the inner side of the yoke part of the base so as to correspond to the tracking coils. Lens actuator for optical pickup, characterized in that consisting of a magnet. 5. The optical actuator of claim 4, wherein the tracking coils are arranged in pairs so that each pair is positioned to face each other. The optical actuator of claim 3 or 4, wherein the focusing permanent magnet and the tracking permanent magnet are disposed at 180 degree intervals so as to face each other. The optical pickup lens according to claim 3 or 4, wherein the support part of the lens holder is provided with iron pieces for generating magnetic stiffness in the focusing direction and the tracking direction at the same positions as the tracking coils, respectively. Actuator.