JP2000113482A - Optical pickup device and optical disk device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make the optical pickup device and the optical disk device suitable for a miniaturized and thin type by controlling a tilt of an object lens. SOLUTION: This is an optical pickup device comprising an object lens 7 for collecting light, an object lens barrel 40 for holding it, wires 49 for supporting the object lens barrel 40 and elastic members 47 for tilting, and yoke bases 52 for supporting and fixing the wires 49 and magnets 54. Here, the object lens barrel 40 has a circular space part for guiding light to the object lens 7 and approximately rectangular opening parts for inserting the magnets 54 therein, and has the elastic members 47 for tilting of which one end is fixed to the middle part of the approximately rectangular opening parts with respect to the tangential direction, and the object lens barrel 40 is born to be able to rotate in the tangential direction centering the elastic members 47 for tilting.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a high-density disc,
The present invention relates to an optical pickup device used for recording and reproducing an optical disk such as a compact disk, and an optical disk device using the optical pickup device.

[0002]

2. Description of the Related Art Optical disks have been widely used because of their advantages such as easy handling and large storage capacity. As a result, as a result of using a poor material or repeating the number of times of use, a situation in which an optical disk surface is warped has been used. On the other hand, in order to exhibit these advantages of the optical disk, it is necessary that the optical pickup irradiates the optical disk vertically with light. However, the above-mentioned condition is not satisfied in an optical disk having "warp", and accurate reproduction cannot be performed.

[0003] Therefore, measures are taken to adjust the position of the shaft that supports and guides the optical pickup 3 in anticipation of "warpage" by adjusting the position of the shaft, and to adjust the inclination of the spindle motor unit 2 for rotating the optical disk. Was done. But,
Since the "warp" was not uniform, the adjustment was not suitable for all optical disks.

Further, a method has been proposed in which an optical pickup is tilted following an optical disk. For example, JP-A-8-
As disclosed in Japanese Patent No. 106641, an optical pickup of a type in which a coil and a magnet are arranged around an objective lens to tilt the objective lens. However, since these optical pickups are generally configured to be supported by a plurality of elastic bodies, a tilt control for extending a certain group of elastic bodies and compressing the other group of elastic bodies (described later). Tangential displacement).

[0005]

As a computer apparatus using an optical disk as an external storage medium is becoming smaller and lighter, it is required that the computer apparatus can be used anytime and anywhere while carrying the computer apparatus. Therefore, an optical disk apparatus using an optical disk is also required to be smaller, lighter, and thinner. However, in the above-described invention, since the coil and the magnet are arranged around the objective lens, the block including the objective lens becomes large, and there is a limit in reducing the size and thickness of the optical pickup device.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and provides an optical pickup device having a structure suitable for miniaturization and thinning, which can easily perform tilt control of an objective lens. It is an object of the present invention to provide an optical disk device using the optical pickup device.

[0007]

According to the present invention, there is provided an optical pickup device comprising: an objective lens for condensing light emitted from a light source onto an optical disk; lens holding means for holding the objective lens;
An optical pickup device comprising: a plurality of elastic supporting means for movably elastically supporting a lens holding means; and supporting means for supporting and fixing a driving means for supporting and fixing the elastic supporting means and movably driving the lens holding means. The lens holding means has a circular space for holding the objective lens and guiding the light emitted from the light source to the objective lens and a substantially rectangular opening for inserting the driving means, and the elastic support means has one end fixed to the support means. First elastic support means and second elastic support means having one end fixed to a substantially central portion of the substantially rectangular opening of the lens holding means in the tangential direction, wherein the lens holding means has a second elastic support means. An optical pickup device characterized by being supported so as to be rotatable in a tangential direction about a means.

With the above arrangement, it is possible to provide an optical pickup device capable of performing tilt control in the radial and tangential directions. Therefore, for example, even if radial and tangential skews occur due to the surface deflection of the optical disk, these can be corrected. In addition, the skew margin is expanded by performing tilt control, and reproduction and recording can be reliably performed even on a high-density optical disk or a low-precision optical disk. Furthermore,
A small and thin optical pickup device can be configured by improving the space utilization efficiency of the tilt control mechanism, and the optical disk device using the optical pickup device can be reduced in size and thickness.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Claims 1 and 2 of the present invention
According to the invention described in the above, an objective lens for condensing the light emitted from the light source on the optical disc, a lens holding means for holding the objective lens, a plurality of elastic support means for movably elastically supporting the lens holding means, A supporting means for supporting and fixing the supporting means and supporting and fixing a driving means for movably driving the lens holding means, wherein the lens holding means holds the objective lens and outputs the light emitted from the light source to the objective lens. The elastic support means has a first elastic support means fixed at one end to the support means and a substantially rectangular opening part of the lens holding means at one end. And a second elastic support means fixed to a substantially central portion of the lens in the tangential direction, and the lens holding means has a tangential direction centered on the second elastic support means. That is rotatably supported is an optical pickup apparatus according to claim. In particular, the lens holding means is characterized in that the circular space portion and the substantially rectangular opening portion are arranged on opposite sides with respect to the objective lens, and an optical path for guiding light emitted from the light source to the objective lens exists in the circular space portion. It is assumed that.

With the above arrangement, the skew between the optical disk and the objective lens can be corrected in both the tangential direction and the radial direction. Then, since the optical pickup can reliably irradiate the optical disk with light vertically, reproduction and recording can be performed on a higher-density optical disk (such as an optical disk using blue short-wavelength laser light) and a low-precision optical disk. It can be done reliably. Furthermore, since the magnetic circuit is arranged on one side with the objective lens as the center and the optical system is arranged on the other side on the other side, the space use efficiency is improved and a thin and small optical pickup device can be configured. In addition, the entire optical disc device can be made thinner and smaller.

According to a third aspect of the present invention, there is provided an objective lens for condensing light emitted from a light source on an optical disk, lens holding means for holding the objective lens, and moving the lens holding means. An optical pickup apparatus comprising: a plurality of elastic support means for elastically supporting the lens support means; and a support means for supporting and fixing a drive means for supporting and fixing the elastic support means and movably driving the lens holding means, the lens holding means comprising: Has a circular space in which an optical path for holding the objective lens and guiding the light emitted from the light source to the objective lens and a substantially rectangular opening through which the driving means is inserted, and the circular space and the substantially rectangular opening are formed by the objective lens. The elastic support means is disposed on the opposite side with respect to the first elastic support means, one end of which is fixed to the support means, and one end of which is a tanger of a substantially rectangular opening of the lens holding means. Second elastic support means fixed to a substantially central portion in the char direction, wherein the lens holding means is rotatably supported in the tangential direction about the second elastic support means. Optical pickup device.

[0012] In particular, according to a fourth aspect of the present invention, the driving means includes four focusing driving means capable of generating a driving force in the focusing direction independently of each other, and the size and direction of each focusing driving means are individually determined. By controlling, it is possible to drive to rotate the lens holding means in the tangential direction about the second elastic support means as a center axis, and the invention according to claim 5 is characterized in that: The driving means includes four focusing driving means capable of generating a driving force in the focusing direction independently of each other, and by individually controlling the size and direction of the focusing driving means, the tangential direction is used as the rotation axis. The present invention is characterized in that it can be driven to rotate the lens holding means in the radial direction. A drive means including four focusing drive means capable of generating a driving force in the focusing direction and arranged in a substantially rectangular opening portion's holding means independently of each other,
An optical path for guiding the light emitted from the light source to the objective lens is disposed in the circular space, and an optical component relating to the optical path and a component relating to the driving unit are disposed on the same surface on opposite sides with respect to the objective lens. It is characterized by the following.

With the above arrangement, the skew between the optical disk and the objective lens can be corrected in both the tangential direction and the radial direction. Then, since the optical pickup can reliably irradiate the optical disk with light vertically, reproduction and recording can be performed on a higher-density optical disk (such as an optical disk using blue short-wavelength laser light) and a low-precision optical disk. It can be done reliably. Furthermore, since the magnetic circuit is arranged on one side with the objective lens as the center and the optical system is arranged on the other side on the other side, the space use efficiency is improved and a thin and small optical pickup device can be configured. In addition, the entire optical disc device can be made thinner and smaller.

According to a seventh aspect of the present invention, there is provided an objective lens for condensing light emitted from a light source onto an optical disk, lens holding means for holding the objective lens,
An optical pickup device comprising: a plurality of elastic supporting means for movably elastically supporting a lens holding means; and supporting means for supporting and fixing a driving means for supporting and fixing the elastic supporting means and movably driving the lens holding means. The lens holding means has a circular space in which an optical path for holding the objective lens and guiding the light emitted from the light source to the objective lens is present, and a substantially rectangular opening through which the driving means is inserted. And four annular coils wound around a plane parallel to the surface of the optical disc in each of four substantially divided areas of the substantially rectangular opening. The driving means has four pole pieces erected on the support means and permanent magnets fixed to each of the pole pieces and magnetized with magnetic poles in the radial direction of the optical disk. The first elastic support means having one end fixed to the support means and the substantially rectangular opening portion of the lens holding means, wherein the magnetic pole pieces and the permanent magnets are respectively inserted into the four annular coils when they are fully inserted. And second elastic support means having one end fixed at a substantially central portion in the tangential direction of the lens. The lens holding means is supported rotatably in the tangential direction about the second elastic support means. An optical pickup device characterized in that:

In particular, the invention according to claim 8 of the present invention comprises a plurality of conductive linear elastic bodies in which the first elastic supporting means and the second elastic supporting means are mutually insulated by an insulating elastic member. It is characterized by being formed. The invention according to claim 9 of the present invention is characterized in that the insulating elastic member is formed of silicon rubber. According to a tenth aspect of the present invention, the substantially rectangular opening has a second annular coil wound and formed in a plane perpendicular to the surface of the optical disc, and the second rectangular coil is formed in the tangential direction of the substantially rectangular opening. The second annular coil is arranged substantially at the center in the tangential direction.

With the above configuration, a moving coil type optical pickup device can be formed, and by giving a difference between the current values of the four focus coils, the tilt control of the radial direction and the tangential direction with respect to the optical disk can be performed. It is possible. By controlling the currents of the four focus coils while maintaining the difference between the current values, the focus operation can be performed while maintaining the tilt control. Moreover, since the wire and the tilt elastic member also serve as the coil power supply line, the structure can be simplified and the size can be reduced.

Thus, the skew between the optical disk and the objective lens can be corrected in both the tangential direction and the radial direction. In addition, since the optical pickup can reliably irradiate the optical disk with light vertically, reproduction and recording can be performed on a higher-density optical disk (such as an optical disk using a blue short-wavelength laser beam) or a low-precision optical disk. It can be done reliably. Furthermore, since the magnetic circuit is arranged on one side with the objective lens as the center and the optical system is arranged on the other side on the other side, the space use efficiency is improved and a thin and small optical pickup device can be configured. In addition, the entire optical disc device can be made thinner and smaller.

According to the eleventh to eighteenth aspects of the present invention, the objective lens for condensing the light emitted from the light source on the optical disk, the lens holding means for holding the objective lens, and moving the lens holding means An optical pickup apparatus comprising: a plurality of elastic support means for elastically supporting the lens support means; and a support means for supporting and fixing a drive means for supporting and fixing the elastic support means and movably driving the lens holding means, the lens holding means comprising: Has a circular space in which an optical path for holding the objective lens and guiding the emitted light of the light source to the objective lens is present, and a substantially rectangular opening through which the driving means is inserted, and wherein the circular space and the substantially rectangular opening are Permanent magnets are disposed on opposite sides of the objective lens and are magnetized in the radial direction of the optical disk among the substantially rectangular openings, and the driving means is disposed on the supporting means. A plurality of coil means which is,
When the driving means is inserted through the substantially rectangular opening, the coil means faces the permanent magnet, the elastic supporting means has a first elastic supporting means having one end fixed to the supporting means, and a tanger at the substantially rectangular opening of the lens holding means. Second elastic support means, one end of which is fixed to a substantially central portion in the axial direction, wherein the lens holding means is supported rotatably in the tangential direction about the second elastic support means. This is an optical pickup device characterized by the following.

In particular, claim 12 to claim 13 of the present invention.
In the invention described in (1), the first elastic support means and the second elastic support means are formed of a plurality of conductive linear elastic bodies with an insulating elastic member interposed therebetween, and the insulating elastic member is formed of silicon rubber. It is characterized by having been done. Also,
According to a fourteenth aspect of the present invention, there is provided a tracking coil formed by winding a coil means on a core member formed of a ferromagnetic material in a plane perpendicular to the optical disk surface and winding the coil in a plane parallel to the optical disk surface. And a molded focus coil. Further, claim 1 of the present invention
The fifth to eighteenth aspects of the invention are characterized by the shape and arrangement of the permanent magnet for forming the magnetic field.

With the above arrangement, only the magnet is arranged in the movable portion, so that a robust moving magnet type optical pickup device can be constructed. In particular, it is possible to suppress vibration of the elastic member for tilt and the wire so that natural vibration does not occur in the entire movable part.
Furthermore, by giving a difference between the current values of the four focus coils, tilt control of the optical disk in the radial direction and the tangential direction can be performed. By controlling the currents of the four focus coils while maintaining the difference between the current values, the focus operation can be performed while maintaining the tilt control.

Thus, the skew between the optical disk and the objective lens can be corrected in both the tangential direction and the radial direction. In addition, since the optical pickup can reliably irradiate the optical disk with light vertically, reproduction and recording can be performed on a higher-density optical disk (such as an optical disk using a blue short-wavelength laser beam) or a low-precision optical disk. It can be done reliably. Furthermore, since the magnetic circuit is arranged on one side with the objective lens as the center and the optical system is arranged on the other side on the other side, the space use efficiency is improved and a thin and small optical pickup device can be configured. In addition, the entire optical disc device can be made thinner and smaller.

According to the present invention, the thickness from the lower surface of the optical disk to the lower surface of the optical disk device is 7.6 mm or less when the optical disk is mounted. Claim 1 to Claim 1
8. An optical pickup device according to item 8, further comprising an optical disk device using the optical pickup device, and in particular, using the optical pickup device, the thickness of the entire device is 12.7 mm. An optical disk device having the following configuration.

When the optical pickup device of the present invention configured as described above is used, the thickness (T) of the optical pickup on which the optical disk is mounted is extremely small, so that the thickness (TC) of the entire optical disk device is also 12.7 mm (1). / 2 inches) or less. As a result, a computer device using this optical disk device can be configured to be extremely thin. Alternatively, a computer device using only one conventional optical disk device can be equipped with two optical disk devices.

(Embodiment 1) An embodiment of the present invention will be described below with reference to the drawings. First, the optical pickup device will be described. FIG. 1 is a plan view of an optical pickup device according to Embodiment 1 of the present invention, and FIG.
FIG. 2 is a sectional view taken along line II. FIG. 3 is a plan view of the optical pickup of FIG. 1, and FIG. 4 is a sectional view taken along line II-II of FIG.

In each of FIGS. 1 to 4, reference numeral 1 denotes an optical disk, and a high-density optical disk (DVD) having a thickness from the lower surface (front surface) to the recording surface of about 0.6 mm and a thickness from the recording surface of about 0.6 mm. A 1.2 mm low density optical disc (CD) can be used. Reference numeral 2 denotes a motor unit, and an optical disc 1
Turntable (not shown) and optical disc 1
Optical disc 1 including a mechanism (not shown) for clamping
To rotate. Reference numeral 3 denotes an optical pickup, which is a generic name including an actuator unit 8 that supports an optical system 6 and an objective lens 7 and a carriage 9 that holds these members and can move in the radial direction of the optical disc 1 as described later. It is.
Reference numeral 4 denotes a feed unit, which controls the carriage 9 to move the optical disc 1
, A driving mechanism for moving in the radial direction. 5
Is a module base, and the feed unit 4 described above,
The motor unit 2 and the optical pickup 3 are mounted in a predetermined configuration. Then, as shown in FIG. 1, a state in which the feed unit 4, the motor unit 2, and the optical pickup 3 are assembled on the module base 5 is collectively referred to as an optical pickup device.

Next, the driving mechanism of the feed unit 4 will be described. A feed motor 34 has a motor gear 35 attached to its output shaft. Further, a train gear 36 meshing with the motor gear 35 to reduce the rotation of the feed motor 34 meshes with a screw shaft gear 37 meshing with the train gear 36. A spiral groove is formed on the outer periphery of the screw shaft 38 to which the screw shaft gear 37 is fixed. Screw shaft 3
The rack 39 meshes with the spiral groove 8. Rack 3
Numeral 9 is attached to the carriage 9 via a leaf spring.
The carriage 9 engages with the support shaft 32 and the guide shaft 33 provided on the module base 5,
The optical disk 1 can be moved in the radial direction. In this state, by rotating the feed motor 34 in the forward and reverse directions, the rack 39 moves along the groove formed on the screw shaft 38, and the optical pickup 3 can move in the radial direction of the optical disc 1. It is a mechanism.

Next, the optical system 6 will be described. The optical system 6 includes a light source having two different wavelengths and an optical lens system. First, the light source of the first wavelength has a wavelength of 635-65.
An optical unit 11 that emits a laser beam A of 0 nm, in which a semiconductor laser and a photodetector including a light receiving element are integrally formed. The light source of the second wavelength has a wavelength of 78
An optical unit 12 that emits a laser beam B of 0 nm, and includes a semiconductor laser, a diffraction grating that generates three beams from the laser beam B, a diffraction grating that guides reflected light from the optical disc 1 to a detector, and light detection including a light receiving element. The vessel is integrally configured. Further, the optical units 11 and 12 are respectively provided with volumes 13 and 14 for adjusting the amount of emitted laser light of the internal semiconductor laser. The optical unit 6 on the short wavelength side includes a superimposing circuit 15 for superimposing the optical power of the internal semiconductor laser and a shield case 16 that covers the entire area of the superimposing circuit 15 and shields unnecessary radiation. Be placed.

Next, the optical lens system will be described. Reference numeral 21 denotes a wedge beam splitter having a wavelength of 635 to 650.
A film that reflects the laser light A having a wavelength of 780 nm and transmits the laser light B having a wavelength of 780 nm is formed. Reference numeral 22 denotes a collimator lens, which converts the diffused light into substantially parallel light with respect to the laser light A, and reduces the diffusion angle of the diffused light with respect to the laser light B.

Further, the light sources of the optical units 11 and 12 are arranged in the following relationship with each other. Optical unit 11
Is disposed at a position where the laser light A having a wavelength of 635 to 650 nm becomes substantially parallel light after passing through the collimator lens 22. The optical path distance in the air from the laser light source of the optical unit 11 to the collimator lens 22 at this time is L1. On the other hand, the arrangement position of the optical unit 12 is
The laser light B having a wavelength of 780 nm is set at a position where the diffusion angle of the diffused light decreases after passing through the collimator lens 22. The optical path distance in the air from the laser light source of the optical unit 12 to the collimator lens 22 at this time is L2. The optical units 11 and 12 are arranged at positions where the respective light sources have a relationship of 0.55 ≦ L2 / L1 ≦ 0.75.

Reference numeral 23 denotes a polarization hologram, which changes the transmission state of the laser beams A and B according to the wavelength of the laser beams A and B. That is, the polarization hologram 23 has a wavelength of 635-6.
A wavelength plate that becomes a 波長 wavelength plate for a laser beam A of 50 nm, a wavelength plate that becomes a 1/1 wavelength plate for a laser beam B of 780 nm, and a polarization hologram diffracted by P or S wave are integrally formed. It is configured. In addition, wavelength 635-650nm
Laser beam A having a wavelength of 780 nm
Is coated with a wavelength filter that reflects light, and in the case of laser light B having a wavelength of 780 nm, the numerical aperture is approximately 0.1.
It is coated in a shape having 45 openings. Reference numeral 24 denotes a rising mirror that changes the optical axis direction of the laser beams A and B to change the optical axis from a direction substantially parallel to the optical disk 1 to a direction substantially perpendicular to the optical disk 1 toward the objective lens 7.

The objective lens 7 focuses the laser beams A and B on the recording surface of the optical disc 1. In particular, the wavelength 635
The laser beam A of 650 nm is formed with a numerical aperture of 0.6 so as to be focused on a high-density optical disc into a light spot having a diameter of about 1 μm. Reference numeral 8 denotes an actuator section, which supports the objective lens 7 such that the objective lens 7 can follow the optical disk 1 in a focus direction and a tracking direction.

These two optical units 11 and 12 are:
Switching is performed according to the type of the optical disc 1 for recording and reproduction.
The optical unit 11 is used for a high-density optical disk whose thickness up to the recording surface is about 0.6 mm. The optical unit 12 is used for a low-density optical disk whose thickness up to the recording surface is about 1.2 mm.

Next, the actuator section will be described with reference to the drawings. 5 is a plan view of the actuator section of FIG. 3, FIG. 6 is a side view of FIG. 5 viewed from arrow C, and FIG.
FIG. 3 is a sectional view taken along line III-III. 5 to 7, the actuator section 8 includes a movable portion and a fixed portion.

First, the movable part will be described. The objective lens 7 is fixed to the objective lens holding cylinder 40 by means such as bonding. The objective lens holding cylinder 40 is supported by two tilt elastic members 47 and attached to the suspension holder 50 via a relay board member 48 and four wires 49.

The objective lens holding cylinder 40 has a frame type structure having a circular space and a substantially rectangular opening, and the objective lens 7 is fixed to the circular space with an adhesive or the like. On the other hand, a plurality of coils, which will be described in detail below, are fixed to the substantially rectangular opening with an adhesive or the like. First, almost four of the openings
A first focus coil 41 at each of the four equally sized corners;
Second focus coil 42, third focus coil 4
The third and fourth focus coils 44 are fixed. Each focus coil is a rectangular solenoid wound around a surface parallel to the surface of the optical disk and stacked in the focusing direction.

Further, the first focus coil 41 and the third
The first tracking coil 45 is fixed in a gap between the focus coil 43. Similarly, a second tracking coil 46 is fixed in a gap between the second focus coil 42 and the fourth focus coil 44. Also,
Each tracking coil is a solenoid wound around a surface perpendicular to the surface of the optical disk and stacked in the radius (tangential) direction of the optical disk. Numeral 60 denotes a counter balancer which adjusts the weight balance of all the parts assembled in the objective lens holding cylinder 40 and moves the center of gravity of the movable part to the movable center (the intersection of the center line of the objective lens 7 and the center line of the tilt elastic member 47). ) To ensure desired operating characteristics.

The tilting elastic member 47 supports the objective lens holding cylinder 40. One end of the tilt elastic member 47 is fixed to the side surface of the objective lens holding cylinder 40, and the other end is fixed to the relay board member 48 by soldering or the like. The position at which the tilting elastic member 47 is fixed to the objective lens holding barrel 40 is the center of the substantially rectangular opening, and the side surface of the intermediate portion between the first focus coil 41 and the third focus coil 43. FIG. 5 is a side view of an intermediate portion between the second focus coil 42 and the fourth focus coil 44 (see FIG. 5).

The relay board member 48 has two functions, and fixes the tilt elastic member 47 and the wire 49.
The conduction of the wire 49 is connected to the relay board member 48. Therefore, the relay board member 48 is formed of a rigid body that supports the tilt elastic member 47 and the wire 49. Further, the relay board member 48 and the wires 49 are fixed by soldering. The other ends of the four wires 49 pass through the suspension holder 50 and are fixed by soldering to a flexible board 51 attached to the back surface of the suspension holder 50.
Silicon-based gel for damping the vibration of the wire 49 is applied to the through hole of the suspension holder 50. The elasticity of the wire 49 is set weaker than that of the tilt elastic member 47. Therefore, the objective lens holding cylinder 4
The behavior of 0 is first affected by the elasticity of the wire 49.

Next, the fixed portion will be described. The suspension holder 50 described above is fixed to the carriage 9 together with the yoke base 52. The yoke base 52 has four yoke poles 53 projecting therefrom, and magnets 54 are fixed to the surfaces of the yoke poles 53 facing each other. The yoke base 52 and the yoke pole 53 are both formed of a ferromagnetic material, and form a magnetic circuit together with the magnet 54.

When the fixed portion constructed as described above is fixed to the carriage 9, the arrangement is as follows. That is, the suspension holder 50 is fixed to the carriage 9 by means such as bonding or soldering after optical adjustment of the objective lens 7 is performed. Suspension holder 5
At 0, the yoke base 52 is screwed and fixed. Each of the four yoke poles 53 to which the magnet 54 is fixed is a first focus coil 41 and a second focus coil 4.
Second, the third focus coil 43 and the fourth focus coil 44 are inserted into the respective central space portions and fixed while maintaining the positional accuracy. Accordingly, the four focus coils 41 to 44 and the two tracking coils 45 and 46 are arranged in the magnetic field generated by the magnet 54. Thus, the suspension holder 50 is supported at the neutral position by the two tilt elastic members 47 and the four wires 49.

The circular space of the objective lens holding tube 40 constitutes a space other than the objective lens 7 and its reinforcing ribs (see FIGS. 6 and 7). This space portion is a space for securing the optical paths of the laser beams A and B (see FIGS. 3 and 4). In this manner, the laser beams A and B can be guided horizontally below the objective lens 7 from the opposite side of the magnetic circuit. That is, since the magnetic circuit is arranged on one side with the objective lens 7 as the center and the optical system 6 is arranged on the other side on the opposite side, the optical system 6 and the actuator section 8 can be arranged on the same carriage 9. Becomes
The space use efficiency is improved, and the thin and small optical pickup 3 can be configured.

Referring again to FIGS. 5 and 6, the outer shape of the actuator section 8 of the present invention configured as described above has a width W in the tracking direction; a length of the coil portion in the tangential direction 2D1;
6.2 mm Length to the objective lens in the tangential direction D;
8.8 mm Thickness in the focusing direction T1; 5.5 mm or less Thickness of the optical pickup device with the optical disc mounted thereon T;
It is configured to 7.6 mm or less. This is an outer shape whose projected area in length and width is equal to or slightly larger than that of the conventional actuator section. Further, the thickness is equivalent to the thinnest one of the conventional actuator section.

FIG. 8 is an optical disk device using the optical pickup device of the present invention and a sectional view taken along the line IV-IV. 8, reference numeral 81 denotes a turntable on which the optical disc 1 is placed. Reference numeral 82 denotes a spindle motor that drives the turntable 81 to rotate. A tray 83 pulls out the optical pickup device together with the carriage 9 from the optical disk device. Reference numeral 84 denotes a case which accommodates the tray 83 and forms an external housing of the optical disk device. T in the drawing has the same value as T shown in FIG. 6, and the thickness T (from the lower surface of the optical disk 1 to the lower surface of the actuator section 8) when the optical disk is mounted on the optical pickup device is 7.6 mm or less.

Further, TC represents the thickness of the entire optical disk apparatus, and is a value obtained by adding the above-mentioned T to the storage mechanism of the tray 83, the rotation mechanism of the optical disk 1, and its extra space.
When the optical pickup device of the present invention is used, since T is extremely small, the thickness TC of the entire optical disk device is also 12.7.
mm (１ ／ inch) or less.
As a result, a computer device using this optical disk device can be configured to be extremely thin. Alternatively, a computer device using only one conventional optical disk device can be equipped with two optical disk devices.

The configuration described above constitutes a moving coil type in which a coil is arranged on a movable portion. Therefore, the four wires 49 and the two elastic members for tilt 47 also have a function of supplying current to each coil. FIG. 9 is a sectional view of the tilt elastic member 47, and FIG.
FIG. That is, the four wires 49 and the two tilt elastic members 47 are linear conductive elastic members having both functions of an elastic member and a conductive wire. Whether the cross-sectional shape is circular or rectangular is determined by selecting a cross-sectional shape suitable for exhibiting the elastic function described in the operation described later.

Therefore, as shown in FIGS. 9 and 10, both the wire 49 and the tilting elastic member 47 are provided between a plurality of conductive linear elastic members 55 arranged at a predetermined interval, and are provided with silicon damping silicon. This is a structure in which an insulating gel 56 such as a system is interposed. In the example shown in both figures, one wire 49 corresponds to two circuits and four wires to eight circuits, and the tilt elastic member 47 is one.
It is possible to supply currents corresponding to three circuits in this case and six circuits in two cases.

As the silicon-based insulating gel 56, for example, a material such as silicon rubber is preferably used. Such a material electrically insulates each conductor of the conductive linear elastic body 55 from each other. At the same time, the elastic member 47 and the wire 49 have elasticity to the extent that the elasticity of the wire 49 is not impaired. Can be

It is to be noted that the present invention is not limited to the plurality of conductive linear elastic members 55 described in the above example, and that the number of divisions can be increased or decreased as appropriate in design. The number of circuits that are insufficient even with the wires 49 and the tilting elastic members 47 may be supplied to each focus coil and each tracking coil by another wiring (for example, a flexible printed conductor or the like is not shown).

The reproducing operation of the optical discs 1 having different recording densities will be described below. First, a case of reproducing a signal from a high-density optical disk will be described. Optical unit 1
Wavelength 635-650n emitted from one semiconductor laser
m laser light A is reflected by the wedge beam splitter 21 and then becomes substantially parallel light by the collimator lens 22.
The light passes through the polarization hologram 23, is reflected by the rising mirror 24, and enters the objective lens 7. The laser beam A is condensed by the objective lens 7, enters the high-density optical disk, and forms an image on the recording surface of the high-density optical disk located at about 0.6 mm in the thickness direction. The reflected light from the recording surface again passes through the objective lens 7 and reaches the light receiving element of the optical unit 11 along the reverse path.

On the other hand, when recording / reproducing a signal from a low-density optical disk, a laser beam B having a wavelength of 780 nm emitted from a semiconductor laser of the optical unit 12 is formed into three beams while passing through a diffraction grating (not shown). , Through the wedge beam splitter 21. Next, the light passes through the collimator lens 22 and is transmitted through the polarization hologram 23 after being subjected to an aperture limitation of about 0.45 in numerical aperture. Further, the light is reflected by the rising mirror 24 and enters the objective lens 7.
The laser beam B is condensed by the objective lens 7 and is incident on the low-density optical disk, and the laser beam B is approximately 1.1 in the thickness direction of the low-density optical disk.
An image is formed on the recording surface located at 2 mm. The light reflected from the recording surface again passes through the objective lens 7 and enters the optical unit 12 through the reverse path. Light reflected from the recording surface is diffracted by the diffraction grating and reaches the photodetector.

In the course of the recording / reproducing operation described above, focusing control and tracking control of the objective lens 7 are performed to form laser beams A and B on the recording surface. The operation of the actuator section 8 necessary for the focusing control and the tracking control will be described below.

First, the operation of the tracking control will be described. In FIG. 5, the first tracking coil 45 and the second tracking coil 46 are connected in series. The strands on one side constituting these tracking coils are wound perpendicularly to the plane of FIG. 5 (perpendicular to the plane of the optical disc 1). Further, one side constituting these tracking coils is located in a magnetic field formed by the facing magnet 54. Therefore, when a current is supplied in a predetermined direction to the first tracking coil 45 and the second tracking coil 46, the first tracking coil 45 and the second tracking coil 46 are applied to the first tracking coil 45 and the second tracking coil 46 in the radial direction shown in FIG. An electromagnetic force is generated in the vertical direction. As a result, the objective lens holding cylinder 40 elastically deforms the four wires 49 and moves in the tracking direction.
Since the electromagnetic force in the tracking direction acts on the tilt elastic member 47 in the buckling direction, the tilt elastic member 47 is not deformed.

Next, the operation of the focusing control will be described. The current is controlled independently for each of the first to fourth focus coils 41 to 44. At this time,
Each focus coil 4 is moved so that the objective lens holding cylinder 40 is displaced upward (or downward) in the focusing direction.
The current is controlled to flow from 1 to 44. At this time, each of the focus coils 41 to 44 is wound in a plane surrounding the yoke pole 53 and the magnet 54 in a plane parallel to the plane of FIG. 5 (in a plane parallel to the plane of the optical disc 1).
Further, one side of each of the focus coils 41 to 44 is located in a magnetic field formed by the facing magnet 54. Therefore, by the above-described current control, each of the focus coils 41 according to Fleming's left hand rule
4 to 4, an electromagnetic force is generated in a direction perpendicular to the paper surface of FIG. 5 (focusing direction of FIG. 6). As a result, the four wires 49 are deformed, and the objective lens holding cylinder 40 holding the objective lens 7 is displaced in the focusing direction. The tilt elastic member 47 has a predetermined bending rigidity in the focusing direction (as described above, the elasticity of the wire 49 is set to be weaker than the tilt elastic member 47). It does not deform and does not affect the movement of the objective lens 7 at all.

Each of the operations in the tracking direction and the focusing direction described above is an operation of moving the objective lens 7 in parallel with the deformation of the four wires 49. On the other hand,
The operation of rotating the objective lens 7, that is, the operation of tilt control (tilt control) in two directions will be described. For example, the first
Current control is performed on the focus coil 41 and the third focus coil 43 so that the objective lens holding cylinder 40 is displaced upward (in a direction approaching the optical disc 1) in the focusing direction. Also, the other second focus coil 42 and the fourth
Current control is performed on the focus coil 44 so that the objective lens holding cylinder 40 is displaced downward (in a direction away from the optical disc 1) in the focusing direction. Then, a moment acts to rotate the objective lens holding tube 40 in the radial direction.
The optical disk 1 is tilted in the radial direction (radial direction) about the rotation axis in the tangential direction passing through the optical disk 1. At this time, the four wires 49 are bent and deformed, and the objective lens holding cylinder 40 can be tilted in the radial direction. It is needless to mention again that the tilting operation in the reverse direction is performed by making the current control in the reverse direction.

The operation of tilt control in another direction will be described. For example, current control is performed on the first focus coil 41 and the second focus coil 42 so that the objective lens holding barrel 40 is displaced upward (in a direction approaching the optical disc 1) in the focusing direction. Also, current control is performed on the third focus coil 43 and the fourth focus coil 44 so that the objective lens holding cylinder 40 is displaced downward (in a direction away from the optical disc 1) in the focusing direction.
Then, a moment acts to rotate the objective lens holding cylinder 40 in the tangential (tangential) direction of the optical disc 1 with the center axis of the tilt elastic member 47 as the center of rotation, and the objective lens holding cylinder 40 causes the tangential of the optical disc 1 to move. It operates to tilt in the (tangential) direction. At this time, the fixed end side of the relay board member 48 of the wire 49 does not displace in the tangential direction as in the related art. This is because displacement in the tangential direction cannot be performed as in the related art. For example, when the four wires 49 are two in the upper group and two in the lower group, the wires 49 in the upper group are not extended and the elastic members in the lower group are not displaced.

However, since a moment centering on the tilt elastic member 47 acts, the tilt elastic member 47 is twisted and deformed, and the objective lens holding cylinder 40 can be tilted in the tangential direction. Furthermore, since the tilt elastic member 47 functions as a torsion bar,
The torsional stress can be easily adjusted by the length of the tilt elastic member 47. It is needless to mention again that the tilting operation in the reverse direction is performed by making the current control in the reverse direction. In this manner, by disposing the tilt elastic member 47 between the objective lens holding tube 40 and the wire 49, the tilting of the objective lens holding tube 40 in the tangential direction is facilitated, and the tilt is controlled with a small driving force. Can be.

As described above in detail, according to the optical pickup device of the present invention, since four focus coils are provided and the current value of each focus coil is given a difference, the radial direction with respect to the optical disc and the tangential It is possible to perform tilt control in the initial direction. By controlling the currents of the four focus coils while maintaining the difference between the current values, the focus operation can be performed while maintaining the tilt control.

Therefore, the skew between the optical disk and the objective lens can be corrected in both the tangential direction and the radial direction. Then, since the optical pickup can reliably irradiate the optical disk with light vertically, reproduction and recording can be performed on a higher-density optical disk (such as an optical disk using blue short-wavelength laser light) and a low-precision optical disk. It can be done reliably.

Further, since the magnetic circuit is arranged on one side with the objective lens as the center and the optical system is arranged on the other side, the space use efficiency is improved and a thin and compact optical pickup device is constructed. In addition, it is possible to reduce the thickness and size of the entire optical disk device.

In the above description, an example in which two tracking coils are used has been described. Therefore, an example in which the present invention is applied to one tracking coil in order to make the structure simpler will be described. FIG. 11 is a plan view of an actuator unit using one tracking coil. In FIG. 11, reference numeral 61 denotes a tracking coil. Comparing with FIG. 5, the other configuration is the same as FIG. 5 except that the shape and arrangement of the tracking coil 61 are different.

The tracking coil 61 is wound in a rectangular shape, and one side of the rectangle is formed by the first focus coil 41 and the third coil.
Similarly, another side of the rectangle is disposed in the gap between the second focus coil 42 and the fourth focus coil 44. Then, these two sides are arranged so as to be located in the magnetic field of the magnet 54 facing the same. Therefore, the direction of the current flowing on one side of the rectangle is opposite to the direction of the current flowing on the other side of the rectangle. For this purpose, the orientation of the magnetic pole formed by the magnet 54 disposed between the first focus coil 41 and the third focus coil 43 and the magnet disposed between the second focus coil 42 and the fourth focus coil 44 The magnetic poles 54 are arranged in the opposite directions to each other.

Thus, one tracking coil 61
Can be used to perform a tracking operation.
The other focusing operation, tilt control operation, and reproduction operation are the same as in the example using two tracking coils. In this way, by using one tracking coil, the structure can be simplified and the mass of the movable portion can be reduced, so that the operation sensitivity of the actuator can be increased and the weight of the optical pickup can be reduced. .

(Embodiment 2) The configuration described in Embodiment 1 above constitutes a moving coil type in which a coil is arranged on a movable portion. On the other hand, it is also possible to configure a moving magnet type in which a magnet is arranged on a movable part. Hereinafter, the moving magnet type actuator will be described with reference to the drawings. FIG. 12 is a plan view of the optical pickup according to the second embodiment of the present invention, and FIG. 13 is a plan view of the actuator section of FIG. FIG.
In FIGS. 2 and 13, reference numeral 3 denotes an optical pickup, and reference numeral 6 denotes an optical system, which is the same as that described in the first embodiment, and will not be described again. Reference numeral 10 denotes a moving magnet type actuator unit, which will be described in detail below.
14 is a side view of FIG. 13 viewed from arrow D, and FIG.
FIG. 5 is a sectional view taken along line VV of FIG. 13 to 15,
The actuator unit 10 includes a movable part and a fixed part.

First, the movable part will be described. The objective lens 7 is fixed to the objective lens holding cylinder 40 by means such as bonding. The objective lens holding cylinder 40 is supported by two tilt elastic members 47 and attached to the suspension holder 50 via a relay board member 48 and four wires 49. The objective lens holding cylinder 40 has a frame type structure having a circular space portion and a substantially rectangular opening portion. The objective lens holding cylinder 40, the tilt elastic member 47, the relay board member 48, the wire 49, and the suspension holder 5
Since each of 0 is the same as that described in the first embodiment, the description will not be repeated. In the moving magnet type described in the present embodiment, the tilting elastic member 47, the relay board member 48, and the wire 49 do not need to have an electrical conduction function.
The function of suppressing vibration by combining the insulating gel 5 and the insulating gel 56 is useful similarly to the moving coil type according to the first embodiment. As a result, it is possible to prevent natural vibration from occurring in the entire movable part.

The above-mentioned objective lens 7 is fixed to the circular space with an adhesive or the like. On the other hand, a plurality of magnets, which will be described in detail below, are fixed to the substantially rectangular openings with an adhesive or the like. First, the first magnet 111 is arranged on a rectangular side closer to the objective lens 7 in the opening, and the second magnet 112 is placed on a rectangular side farther from the objective lens 7 (closer to the suspension holder 50) in the opening. Place. The shapes of the first magnet 111 and the second magnet 112 are formed in substantially parallel flat plates, and have a size matching the side surface of the rectangular side of the objective lens holding cylinder 40.

The polarity of the magnetization is, for example, the first magnet 1
The N pole is magnetized on the objective lens 7 side, and the S pole is magnetized on the back side (substantially rectangular opening portion) side. The N pole is magnetized on the objective lens 7 side (the side of the substantially rectangular opening) of the second magnet 112, and the S pole is magnetized on the back surface (the side close to the suspension holder 50). That is, the substantially rectangular opening is formed by the first magnet 111 and the second magnet 112.
And a magnetic field is formed. Numeral 113 denotes a counter balancer which adjusts the weight balance of all the parts assembled in the objective lens holding cylinder 40 and moves the center of gravity of the movable part to the movable center (the intersection of the center line of the objective lens 7 and the center line of the tilt elastic member 47). ) To ensure desired operating characteristics.

Next, the fixed portion will be described. The suspension holder 50 described above is fixed to the carriage 9 together with the yoke base 52. The yoke base 52 has four cores 62.
Is arranged. The yoke base 52 and the core 62 are both formed of a ferromagnetic material. First, each surface of the core 62 is covered with a resin material to be insulated. A first tracking coil 70, a second tracking coil 71, a third tracking coil 72, and a fourth tracking coil 73 are wound around each of the four cores 62. Each of the tracking coils 70 to 73 is wound so that the winding direction is perpendicular to the optical disk surface, and the winding shape is arranged such that the finished coil cylinder is oriented in the radial direction.

Further, each of the tracking coils 70 to 73
Are wound around the first focus coil 74, the second focus coil 75, the third focus coil 76, and the fourth focus coil 77, respectively. Each of the focus coils 74 to 77 is wound in a plane parallel to the optical disk surface, and is arranged so that the finished coil cylinder is oriented in the focusing direction. Finally, each of the core, the tracking coil, and the coil serves as insulation, protection, fixing of the coil and adhesion to the yoke base 52.
Then, the block of the focus coil is coated with a resin material and adhered to the yoke base 52.

When the fixed portion configured as described above is fixed to the carriage 9, the arrangement is as follows. That is, the suspension holder 50 is fixed to the carriage 9 by means such as bonding or soldering after optical adjustment of the objective lens 7 is performed. Suspension holder 5
At 0, the yoke base 52 is screwed and fixed. Each of the four cores 62 to which the tracking coil and the focus coil are fixed is inserted into the space in the magnetic field formed by the first magnet 111 and the second magnet 112, and is fixed while maintaining positional accuracy. Thus, the suspension holder 50 is supported at the neutral position by the two tilt elastic members 47 and the four wires 49.

Since the outer shape of the objective lens holding cylinder 40 is the same as that described in the first embodiment, the laser beams A and B are guided horizontally below the objective lens 7 from the opposite side of the magnetic circuit. be able to. Accordingly, the magnetic circuit is arranged on one side with the objective lens 7 as the center, and the optical system 6 is arranged on the other side, so that the space use efficiency is improved and the thin and small optical pickup 3 can be constructed. it can. Similarly, the projected area of the length and width is the same or slightly larger than that of the conventional actuator section, and the thickness is equivalent to the thinnest of the conventional actuator section. In addition, since the thickness of the optical disk mounted is 7.6 mm or less, the total thickness of the optical disk device is 12.7 mm.
(１ ／ inch) or less.

The operation of the optical pickup device according to Embodiment 2 of the present invention configured as described above will be described. The recording / reproducing operation of the optical disc 1 is described in the first embodiment.
The description is omitted because it is the same as that of FIG. Objective lens 7
The operation of the actuator section 8 in the focusing control and the tracking control will be described below.

First, the tracking control operation will be described. 13 to 15, the first tracking coil 70, the second tracking coil 71, the third tracking coil 72, and the fourth tracking coil 73 are connected in series. When a current flows through each coil in a predetermined direction, a magnetic field is generated in each core 62 according to the right-hand rule. Then, the magnetic field of each core 62 and the objective lens holding cylinder 40
Between the first magnet 111 and the magnetic field generated by the second magnet 112. As a result, the first magnet 111 and the second magnet 112
A propulsive force based on the repulsive force acts, and the objective lens holding cylinder 40 elastically deforms the four wires 49 and moves in the radial direction. Since the radial thrust acts on the tilting elastic member 47 in the buckling direction, the tilting elastic member 47 is not deformed.

Next, the operation of the focusing control will be described. The current is controlled independently for each of the first to fourth focus coils 74 to 77. At this time,
Each of the focus coils 7 is moved so that the objective lens holding cylinder 40 is displaced upward (or downward) in the focusing direction.
The current flowing from 4 to 77 is controlled. By this current control, a magnetic field according to the right-hand rule is generated in each core 62.
Then, an attractive / repulsive force is generated between the magnetic field of each core 62 and the magnetic field generated by the first magnet 111 and the second magnet 112 of the objective lens holding cylinder 40. As a result, the propulsion force based on the attraction / repulsion force acts on the first magnet 111 and the second magnet 112, and the objective lens holding cylinder 40 elastically deforms the four wires 49 and is displaced in the focusing direction. The tilt elastic member 47 has a predetermined bending rigidity in the focusing direction (as described above, the elasticity of the wire 49 is set to be weaker than the tilt elastic member 47). It does not deform and does not affect the movement of the objective lens 7 at all.

Next, the operation of the two-way tilt control (tilt control) will be described. For example, the first focus coil 7
4 and the third focus coil 76 include the objective lens holding cylinder 4
Current control is performed so that 0 is displaced upward in the focusing direction (direction approaching the optical disc 1). Further, the other second focus coil 75 and fourth focus coil 77
The current is controlled so that the objective lens holding cylinder 40 is displaced downward (in the direction away from the optical disc 1) in the focusing direction. Then, a propulsive force based on the suction / repulsion force is generated, and a moment acts to rotate the objective lens holding tube 40 in the radial (radius) direction. The objective lens holding tube 40 passes through the objective lens 7 in the tangential direction. The optical disc 1 operates so as to be inclined in the radial direction of the optical disc 1 about the rotation axis. At this time, the four wires 49 are bent and deformed, and the objective lens holding cylinder 40 can be tilted in the radial direction. It is needless to mention again that the tilting operation in the reverse direction is performed by making the current control in the reverse direction.

The operation of tilt control in another direction will be described. For example, current control is performed on the first focus coil 74 and the second focus coil 75 such that the objective lens holding cylinder 40 is displaced upward (in a direction approaching the optical disc 1) in the focusing direction. Further, current control is performed on the third focus coil 76 and the fourth focus coil 77 so that the objective lens holding cylinder 40 is displaced downward (in a direction away from the optical disc 1) in the focusing direction.
Then, a propulsion force based on the suction / repulsion force is generated, and a moment acts to rotate the objective lens holding cylinder 40 in the tangential (tangential) direction of the optical disc 1 around the center axis of the tilt elastic member 47 as a rotation center. The objective lens holding cylinder 40 is the tangential (tangential line) of the optical disc 1
It works to tilt in the direction. At this time, the fixed end side of the relay board member 48 of the wire 49 does not displace in the tangential direction. On the other hand, the tilting elastic member 47 is torsionally deformed, so that the objective lens holding cylinder 40 can be tilted in the tangential direction. Furthermore, the torsional stress of the tilt elastic member 47 can be easily adjusted by the length of the tilt elastic member 47. Since the above operation mode is the same as that of the first embodiment, detailed description is not repeated.

As described in detail above, according to the optical pickup device of the second embodiment of the present invention, the optical pickup device is configured as a moving magnet type having four focus coils, and has a radial direction and a tangential direction with respect to the optical disk. Can be controlled. Therefore, the skew deviation between the optical disk and the objective lens can be corrected in both the tangential direction and the radial direction. Since the optical pickup can reliably irradiate the optical disk with light vertically, it can be applied to a higher-density optical disk (such as an optical disk using blue short-wavelength laser light) or a low-precision optical disk, similarly to the moving coil type. Reproduction and recording can be performed reliably. Further, a thin and small optical pickup can be formed, and the entire optical disc device can be made thinner and smaller. Furthermore, since only the magnet is arranged in the movable portion, a robust configuration can be achieved.

A structure for reducing the weight of the moving magnet type actuator described above will be described below. FIG. 16 is a plan view of another actuator section in FIG. A comparison between FIG. 13 and FIG. 16 is that FIG. 16 is characterized in that the magnet is divided into four parts and arranged. That is, 121 is the first magnet, 122 is the second magnet, 123 is the third magnet, and 12
Reference numeral 4 denotes four fourth magnets. First magnet 12
The first and second magnets 122 are arranged symmetrically with respect to an axis in the tangential direction passing through the center of the objective lens 7. Similarly, the third magnet 123 and the fourth magnet 1
Reference numeral 24 is symmetrically disposed with respect to an axis in the tangential direction passing through the center of the objective lens 7. The arrangement of the magnetic poles of the first to fourth magnets 121 to 124 is N pole-S in order from the side closer to the objective lens 7 as in FIG.
Place with poles. Other focus coils 74 to 77
13, the tracking coils 70 to 73, and the wires 49 are the same as those in FIG.

Therefore, the tracking operation, the focusing operation, and the tilt operation are the same as those in FIG. However, the first to fourth magnets 121 to 124 are arranged near the core 62 so that the core 62
The central part away from was simply a space. Therefore, each magnet is divided and downsized, and the total volume of the magnet can be reduced, so that the mass of the movable portion is reduced accordingly.
In addition, the magnetic flux is concentrated near the core 62 and the magnetic flux density is relatively high.
Since the magnets 121 to 124 are arranged, a propulsive force based on the attraction / repulsion force works more strongly. By reducing the mass and increasing the driving force, the operation sensitivity of the actuator unit 10 can be improved.

Another structure for reducing the weight of the actuator section will be described below. FIG. 17 is a plan view of another actuator unit in FIG. FIG. 13 and FIG.
Compared with FIG. 7, FIG. 17 is characterized in that the tracking coils are reduced to two and arranged. That is, 125
Is a first tracking coil, and 126 is a second tracking coil, which is disposed on the core 62 near the objective lens 7. A third focus coil 129 and a fourth focus coil 130 are wound around their outer circumferences. The combination of these tracking coils and focus coils is the same as in the case of FIG. 13 described above.

A first focus coil 127 and a second focus coil 128 are wound around the core 62 farther from the objective lens 7. First focus coil 1
27 and the second focus coil 128 do not have a focus coil at the center, so that even when the required number of turns is wound, the finished shape becomes small. Furthermore, since the first focus coil 127 and the second focus coil 128 need only have a small finished outer shape, a portion of the objective lens holding cylinder 63 close to the frame-type structure suspension holder 50 (the first focus coil 127 and the second focus coil 128). (The portion close to the above) can be made thicker, and the counter balancer can be omitted. Except for the parts described above, the arrangement of the magnetic poles of the magnet and the wires 49 are all the same as in FIG.

Therefore, the tracking operation, the focusing operation, and the tilt operation are the same as those in FIG. However, since the number of tracking coils is reduced and the counter balancer is omitted, the mass of the movable part is reduced, and the operation sensitivity of the actuator unit 10 can be improved.

Further, another configuration for reducing the weight of the actuator section will be described below. FIG.
FIG. 19 is a plan view of another actuator section in FIG.
FIG. 18 is a sectional view taken along line VI-VI of FIG. 18. Compared with FIG. 13 and FIG. 18, FIG. 18 is characterized in that only one magnet is arranged at the center of the substantially rectangular opening. That is,
Reference numeral 64 denotes an objective lens holding cylinder, which has a frame type structure having a circular space portion and a substantially rectangular opening portion. The magnet 131 is arranged in the radial direction at the center of the substantially rectangular opening, and is fixed with an adhesive or the like. The magnet 131 is formed in a flat plate shape, and the magnetization direction is, for example, magnetizing the N pole on the objective lens 7 side and the S pole on the back surface (that is, the opposite side).

The other parts than those described above include the tracking coil and the focus coil,
9 are the same as those in FIG. Accordingly, the tracking operation, the focusing operation, and the tilt operation are the same as the operations in FIG. However, compared to the configuration of FIG. 13, two magnets are reduced to one, so that the mass of the movable part is reduced and the operation sensitivity of the actuator unit 10 can be improved.

Further, another configuration for reducing the weight of the actuator section will be described below. FIG.
FIG. 18 is a plan view of another actuator unit in FIG.
20 is characterized in that the magnet is divided and two magnets are arranged at the center of the substantially rectangular opening. That is, reference numeral 65 denotes an objective lens holding cylinder, which is a frame type structure having a circular space portion and a substantially rectangular opening portion. The first magnet 132 and the second magnet 133 are arranged in the radial direction at the center of the substantially rectangular opening and fixed with an adhesive or the like. Both magnets 132 and 133 are formed in a flat plate shape, and the magnetization direction is, for example, N
The pole and the south pole are magnetized on the back surface (that is, the opposite side).

The other parts than those described above include the tracking coil and the focus coil,
9 are the same as those in FIGS. 13 and 18. Accordingly, the tracking operation, the focusing operation, and the tilt operation are the same as the operations in FIG. However, as compared with the configuration of FIG. 18, the first magnet 132 and the second magnet 133 are arranged near the core 62, and the central portion away from the core 62 is simply a space. Therefore, each magnet is divided and downsized, and the total volume of the magnet can be reduced, so that the mass of the movable portion is reduced accordingly. In addition, the magnetic flux is concentrated near the core 62 and the magnetic flux density is relatively high. Since the first to fourth magnets 121 to 124 are arranged in such a portion, the propulsive force based on the attraction / repulsion force is reduced. Work stronger. By reducing the mass and increasing the propulsion, the actuator unit 1
The operation sensitivity of 0 can be improved.

[0086]

As described above, according to the present invention, the tilt control in the radial direction and the tangential direction is performed as described by taking the moving coil type of the first embodiment and the moving magnet type of the second embodiment as examples. An optical pickup device capable of performing the above-described operations can be provided. Therefore, for example, even if radial and tangential skews due to surface runout of the optical disc are generated, the skew can be corrected. Reproduction and recording can be reliably performed even on a low-precision optical disk.

Further, a small and thin optical pickup device having improved space utilization efficiency by devising the arrangement of the tilt control mechanism can be constructed. The optical disk device using this optical pickup device can be downsized. An excellent effect that the thickness can be reduced can be obtained.

[Brief description of the drawings]

FIG. 1 is a plan view of an optical pickup device according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line II of FIG. 1;

FIG. 3 is a plan view of the optical pickup of FIG. 1;

FIG. 4 is a sectional view taken along line II-II of FIG.

FIG. 5 is a plan view of the actuator section shown in FIG. 3;

FIG. 6 is a side view of FIG.

FIG. 7 is a sectional view taken along line III-III of FIG. 5;

FIG. 8 is an optical disk device using the optical pickup device of the present invention and a cross-sectional view taken along line IV-IV of the optical disk device.

FIG. 9 is a cross-sectional view of the tilt elastic member.

FIG. 10 is a sectional view of a wire.

FIG. 11 is a plan view of an actuator unit using one tracking coil.

FIG. 12 is a plan view of an optical pickup according to a second embodiment of the present invention.

13 is a plan view of the actuator section shown in FIG.

FIG. 14 is a side view of FIG.

FIG. 15 is a sectional view taken along line VV of FIG.

FIG. 16 is a plan view of another actuator unit in FIG. 12;

FIG. 17 is a plan view of another actuator unit in FIG. 12;

FIG. 18 is a plan view of another actuator unit in FIG.

19 is a sectional view taken along line VI-VI of FIG.

FIG. 20 is a plan view of another actuator unit in FIG. 12;

[Explanation of symbols]

 Reference Signs List 1 optical disk 2 motor unit 3 optical pickup 4 feed unit 5 module base 6 optical system 7 objective lens 8, 10 actuator unit 9 carriage 11, 12 optical unit 13, 14 volume 15 superposition circuit 16 shield case 21 wedge beam splitter 22 collimator lens 23 Polarization hologram 24 Start-up mirror 32 Support shaft 33 Guide shaft 34 Feed motor 35 Motor gear 36 Train gear 37 Screw shaft gear 38 Screw shaft 39 Racks 40, 63, 64, 65 Object lens holding cylinder 41 First focus coil 42 Second focus coil 43 third focus coil 44 fourth focus coil 45 first tracking coil 46 second tracking coil 47 elastic part for tilt 48 relay board member 49 wire 50 suspension holder 51 flexible board 52 yoke base 53 yoke pole 54 magnet 55 conductive linear elastic body 56 insulating gel 60, 113 counter balancer 61 tracking coil 62 core 70 first tracking coil 71 second Tracking coil 72 Third tracking coil 73 Fourth tracking coil 74 First focus coil 75 Second focus coil 76 Third focus coil 77 Fourth focus coil 81 Turntable 82 Spindle motor 83 Tray 84 Case 111 First magnet 112 Second magnet 121 first magnet 122 second magnet 123 third magnet 124 fourth magnet 125 first tracking coil 126 Second tracking coil 127 first focus coil 128 second focusing coil 129 third focusing coil 130 fourth focus coils 131 magnet 132 first magnet 133 second magnet

Claims (21)

[Claims] An objective lens for condensing light emitted from a light source onto an optical disk; lens holding means for holding the objective lens; a plurality of elastic support means for movably elastically supporting the lens holding means; A supporting means for supporting and fixing the elastic supporting means and supporting and fixing a driving means for movably driving the lens holding means, wherein the lens holding means holds the objective lens and a light source. A circular space portion for guiding the emitted light to the objective lens, and a substantially rectangular opening through which the driving means is inserted, wherein the elastic support means has a first elastic support having one end fixed to the support means. Means, and second elastic support means having one end fixed to a substantially central portion of the substantially rectangular opening portion of the lens holding means in the tangential direction. It means an optical pickup device characterized by being rotatably supported in the tangential direction about the second resilient support means. 2. The lens holding means, wherein the circular space portion and the substantially rectangular opening portion are arranged on opposite sides of the objective lens as a center, and an optical path for guiding light emitted from a light source to the objective lens is provided. 2. The optical pickup device according to claim 1, wherein the optical pickup device exists in a circular space. 3. An objective lens for condensing light emitted from a light source onto an optical disk, lens holding means for holding the objective lens, a plurality of elastic support means for movably elastically supporting the lens holding means, A supporting means for supporting and fixing the elastic supporting means and supporting and fixing a driving means for movably driving the lens holding means, wherein the lens holding means holds the objective lens and a light source. A circular space where an optical path for guiding the emitted light to the objective lens exists, and a substantially rectangular opening through which the driving unit is inserted, and the circular space and the substantially rectangular opening define the objective lens. The elastic support means are disposed on opposite sides with respect to the center, the first elastic support means having one end fixed to the support means, and one end in front of the lens holding means. Second elastic support means fixed to a substantially central portion of the substantially rectangular opening portion in the tangential direction, wherein the lens holding means is rotatable in the tangential direction about the second elastic support means. An optical pickup device characterized by being supported. 4. The lens driving means includes four focusing driving means capable of generating a driving force in a focusing direction independently of each other, and individually controlling a size and a direction of the focusing driving means to thereby produce the lens. 4. The optical pickup device according to claim 3, wherein the holding means can be driven to rotate in a tangential direction about the second elastic support means as a central axis. 5. The driving means includes four focusing driving means capable of generating a driving force in a focusing direction independently of each other, and individually controlling the size and direction of the focusing driving means to thereby provide a tangential driving means. 4. The optical pickup device according to claim 3, wherein the optical pickup device can be driven to rotate the lens holding means in a radial direction whose direction is a rotation axis. 6. The lens holding means includes: a plurality of focusing driving means capable of generating a driving force in a focusing direction independently of each other; An optical path leading to the objective lens is arranged in the circular space, and an optical component related to the optical path and a component related to the driving unit are arranged on the same surface on opposite sides with respect to the objective lens. The optical pickup device according to claim 3, wherein: 7. An objective lens for condensing light emitted from a light source onto an optical disk, lens holding means for holding the objective lens, a plurality of elastic support means for movably elastically supporting the lens holding means, A supporting means for supporting and fixing the elastic supporting means and supporting and fixing a driving means for movably driving the lens holding means, wherein the lens holding means holds the objective lens and a light source. A circular space where an optical path for guiding the emitted light to the objective lens exists, and a substantially rectangular opening through which the driving unit is inserted, and the circular space and the substantially rectangular opening define the objective lens. The four rectangular winding portions formed in a plane parallel to the surface of the optical disc are disposed in the substantially rectangular opening portion in substantially four divided regions, which are arranged on opposite sides with respect to the center. Has Jo coil, said driving means comprises a permanent magnet magnetized the are erected on the support means and four pole pieces fixed to each of said pole piece pole in the radial direction of the optical disk,
When the driving means is inserted through the substantially rectangular opening, each of the magnetic pole piece and the permanent magnet is inserted through the four annular coils, and the elastic support means has one end fixed to the support means. A first elastic support means, and a second elastic support means having one end fixed to a substantially central portion of the substantially rectangular opening of the lens holding means in a tangential direction, wherein the lens holding means is provided with a second elastic support means. An optical pickup device rotatably supported in a tangential direction about the elastic support means. 8. The apparatus according to claim 1, wherein said first elastic support means and said second elastic support means are formed of a plurality of conductive linear elastic bodies mutually insulated by an insulating elastic member. The optical pickup device according to claim 7. 9. An optical pickup device according to claim 8, wherein said insulating elastic member is formed of silicon rubber. 10. The substantially rectangular opening has a second annular coil wound and formed in a plane perpendicular to the surface of the optical disk. The substantially rectangular opening has a substantially central portion in the tangential direction of the substantially rectangular opening. The optical pickup device according to claim 7, wherein the second annular coil is arranged in a tangential direction. 11. An objective lens for condensing light emitted from a light source on an optical disk, lens holding means for holding the objective lens, a plurality of elastic support means for movably elastically supporting the lens holding means, A supporting means for supporting and fixing the elastic supporting means and supporting and fixing a driving means for movably driving the lens holding means, wherein the lens holding means holds the objective lens and a light source. A circular space where an optical path for guiding the emitted light to the objective lens exists, and a substantially rectangular opening through which the driving unit is inserted, and the circular space and the substantially rectangular opening define the objective lens. A permanent magnet which is disposed on the opposite side with respect to the center and has a magnetic pole magnetized in a radial direction of the optical disc in the substantially rectangular opening; A plurality of coil means arranged in a row, wherein the coil means faces the permanent magnet when the drive means is inserted through the substantially rectangular opening, and the elastic support means has one end fixed to the support means First elastic support means, and second elastic support means having one end fixed to a substantially central portion of the substantially rectangular opening of the lens holding means in the tangential direction, wherein the lens holding means The optical pickup device is supported so as to be rotatable in a tangential direction around the second elastic support means. 12. The apparatus according to claim 1, wherein said first elastic support means and said second elastic support means are formed of a plurality of conductive linear elastic bodies with an insulating elastic member interposed therebetween.
2. The optical pickup device according to 1. 13. The optical pickup device according to claim 12, wherein said insulating elastic member is formed of silicon rubber. 14. A tracking coil wound around a core member formed of a ferromagnetic material in a plane perpendicular to the optical disk surface, and a focus wound around a core member formed of a ferromagnetic material in a plane parallel to the optical disk surface. The optical pickup device according to claim 11, further comprising a coil. 15. The permanent magnet is formed in a parallel plate shape.
12. The optical pickup device according to claim 11, wherein a side closer to the objective lens and a side farther from the objective lens in the substantially rectangular opening are radially arranged. 16. The permanent magnet is formed in a parallel plate shape,
12. The optical pickup device according to claim 11, wherein a side closer to the objective lens and a side farther from the objective lens in the substantially rectangular opening are radially arranged. 17. The permanent magnet is formed in a parallel plate shape,
Of the substantially rectangular opening, the sides closer to the objective lens and the side farther from the objective lens are respectively arranged in the radial direction, and are further divided symmetrically with respect to the axis in the tangential direction passing through the center of the objective lens. 12. The optical pickup device according to claim 11, wherein the optical pickup device is disposed. 18. The permanent magnet is formed in a parallel plate shape,
5. The method according to claim 4, wherein the substantially rectangular opening portion is radially arranged at a substantially central portion in a tangential direction, and is further divided and arranged symmetrically with respect to an axis in the tangential direction passing through the center of the objective lens. 12. The optical pickup device according to item 11. 19. When the optical disk is mounted, the thickness from the lower surface of the optical disk to the lower surface of the optical disk device is 7.6 m.
19. The optical pickup device according to claim 1, wherein the optical pickup device is configured to have a length of m or less. 20. An optical disk device using the optical pickup device according to claim 1, 3, 7, or 11. 21. An optical disc device using the optical pickup device according to claim 19, wherein the thickness of the entire device is 12.7 mm or less.