JP2001243645A - Optical pickup - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correctly control a tilt of an optical disk by a correcting plate provided over an objective lens. SOLUTION: This optical pickup 6 is provided with plural number of first conductive wires 57a-57h which are suspended so as to rock between a base member 52 and an objective lens holder 60, a focus tracking actuator 65 which is provided within the base member 52 and controls the objective lens 50 within the objective lens holder 60 in the focusing direction and the tracking direction of the optical disk 2 through plural number of first wires 57a-57h, plural number of second conductive wires 70a-70d which are suspended so as to rock between the objective lens holder 60 and the correcting plate holder 68, and an actuator 72 for the correcting plate which is provided within the objective lens holder 60 and controls the correcting plate 51 within the correcting plate holder 68 in accordance with a tilt in the tilting direction of the optical disk 2 through plural number of second wires 70a-70d.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical pickup for controlling an inclination angle of a correction plate provided above an objective lens in accordance with an inclination of an optical disk in a tilt direction.

[0002]

2. Description of the Related Art In recent years, MPEG (MOVING PICTURE EXPER
Techniques for recording and reproducing video signals and audio signals on a recording medium by high-density compression using the T GROUP method have been put into practical use.

In the field of AV (AUDIO VISUAL), an optical disc as a recording medium is a DVD (DIGITAL VISUAL).
VIDEO DISC) is attracting attention, and in the field of computers, D
VD-ROM, DVD-RAM, and DVD-RW have attracted attention. For DVD, video and audio signals are MPEG
It has been proposed to record in accordance with the system and record a large amount of data which has never existed in the ROM related art.

Here, a general optical disk recording and / or reproducing apparatus will be briefly described with reference to FIG.

[0005] In the general optical disk recording and / or reproducing apparatus shown in FIG.
The rotation control circuit 3 is configured to rotate the optical disk 2 as a recording and / or reproduction medium, and the control circuit 4
The rotation of the spindle motor 1 is controlled by a command signal from the CPU. The sled motor 5 is configured to move the optical pickup 6 in the radial direction of the optical disc 2, and moves the optical pickup 6 by a drive signal from a sled motor control circuit 7. The optical pickup 6 includes a semiconductor laser, a photodetector, an objective lens, and the like inside. The light beam emitted from the semiconductor laser is condensed in a spot shape on the signal surface of the optical disk by the objective lens, and the signal is output. The return light beam from the surface can be detected by a photodetector.

The sled motor control circuit 7 controls the driving of the sled motor 5 by a command signal from the control circuit 4. Further, the pickup control circuit 8
Performs focus control and tracking control on the optical disk 2 by the objective lens of the optical pickup 6 based on a command signal from the control circuit 4. Also,
The signal processing circuit 9 is a circuit that processes an input signal and / or an output signal for recording and / or reproducing the optical disk 2 by the optical pickup 6. Further, the control circuit 4 outputs a command command to each of the above-described circuits based on a command input via the external interface 10.

In the case of a DVD, for example, in order to record digital data at a high density on the optical disk 2, it is necessary to make the spot size of the light beam smaller than that of a conventional CD (Compact Disc).

Assuming that the radius of the spot size of the light beam is R, the exit angle of the objective lens is θ, and the wavelength of the light beam is λ, the radius R of the spot size of the light beam is substantially expressed by the following equation (1). You.

R = 0.32λ / SINθ (1) As can be seen from equation (1), in order to reduce the spot size of the light beam, the wavelength λ of the light beam is reduced,
Numerical aperture of objective lens NA ｛SINθ (= n × SINθ:
In the case of air, the refractive index n may be increased by 1)｝.

However, for high-density recording and reproduction, it is necessary to use an objective lens having a high numerical aperture and high resolution. However, if the diameter of the objective lens is increased, the optical axis of the light beam with respect to the reproduction surface of the optical disk 2 is increased. The degree of the aberration due to the inclination of the numerical aperture increases in proportion to the cube of the numerical aperture NA. As a result, if the optical axis of the signal reproduction beam is inclined with respect to the reproduction surface of the optical disc 2, optical aberrations occur, crosstalk increases, and the reproduction signal deteriorates.

In the optical disk recording and / or reproducing apparatus, if the optical axis of the signal recording beam is inclined with respect to the recording surface of the optical disk 2, the recording signal may be degraded and pit formation errors may occur.

[0012]

By the way, in an optical disk recording and / or reproducing apparatus, in order to improve the recording capacity on an optical disk, an objective lens having a high aperture ratio is used and a smaller diameter converging spot is used. Recording and / or playback is increasing. In this case, the degree of aberration associated with the tilt, which is the relative inclination of the optical axis of the objective lens with respect to the optical disk, increases in proportion to the cube of the aperture ratio. In positioning the optical axis, more precise positioning is required.

However, when tilt correction control is performed by tilting the entire optical pickup 6 using a DC motor or the like, it is difficult to reduce aberrations because only low-frequency angular displacement can be corrected. The addition of a mechanism for tilting the optical disk increases the size of the entire optical disk recording and / or reproducing apparatus, and furthermore, it is very difficult to match the center of rotation during tilt correction control with the principal point of the objective lens due to lack of space. For this reason, there has been a problem that the height deviation of the objective lens due to the rotation is large, and therefore the size of the objective lens is increased by adding some adjusting means.

Regarding the above-mentioned problems, see JP-A-6-16
As disclosed in Japanese Patent Publication No. 2540, a tilt which is a relative angle between an optical disc and an objective lens is detected, and a driving current flowing through a plurality of focusing coils fixed to a movable body is adjusted based on the detected signal to thereby tilt the optical disc. By performing the correction control, it is possible to correct a tilt from a low frequency to a high frequency.

However, the above-mentioned Japanese Patent Laid-Open Publication No.
In the configuration disclosed in the publication, the magnetic circuit is fixed, and for example, the positions of the plurality of focusing coils with respect to the magnetic flux density distribution of the magnetic circuit change with the movement of the movable body in the tracking direction, The amount of magnetic flux linked to each focusing coil fluctuates.

Accordingly, the drive sensitivity in the tilt correction direction fluctuates depending on the position of the movable body, so that there is a problem that the stability of control is deteriorated. In addition, since the positions of the plurality of focusing coils or tracking coils with respect to the magnetic circuit vary with the movement of the movable body, the relative position between the point of application of the driving force and the movable body varies.

Therefore, when a rotational moment is applied to the movable body by the focusing drive or the tracking drive, an optical axis tilt occurs, and an unstable offset is always added to the tilt correction direction, and the control accuracy in the tilt correction control is reduced. There was a problem of deterioration.

Also, if the tilt angle to be corrected is increased, the movable portion of the objective lens actuator may come into contact with the magnet or yoke during the focusing / tracking operation. There is also a problem that the efficiency of the objective lens is reduced and the drive sensitivity of the objective lens actuator is reduced.

In addition, there is a risk that resonance in the rolling direction or pitching direction may occur in the objective lens actuator due to the tilt correction control.

In order to solve such a problem occurring in the conventional optical pickup, the present invention corrects a tilt from a low frequency to a high frequency, and irrespective of the position of the movable body in the focusing direction and the tracking direction. It is an object of the present invention to provide an optical pickup capable of performing tilt correction control with stable drive sensitivity and controllability at a low cost with a simple structure.

[0021]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and a first invention is to provide a base member serving as a base and an objective lens for condensing a light beam on an optical disk. An objective lens holder mounted therein, a plurality of conductive first wires suspended swingably between the base member and the objective lens holder, a yoke member and a magnet in the base member. Focus / tracking in which a pair of a tracking coil and a focusing coil are attached to each other, and the objective lens is integrally controlled with the objective lens holder in the focusing direction and the tracking direction of the optical disc through the plurality of first wires. Actuator, and provided above the objective lens holder, and for transmitting the light beam from the objective lens. A correction plate holder in which a correction plate for focusing the light beam according to the tilt of the optical disk on the optical disk is mounted, and between the objective lens holder and the correction plate holder. A plurality of second wires that are swingably suspended and have conductivity, and a pair of yoke members, magnets, and correction plate coils are respectively mounted in the objective lens holder, and the correction is performed integrally with the correction plate holder. An optical pickup comprising: a correction plate actuator for controlling a plate according to a tilt of the optical disc in a tilt direction via the plurality of second wires.

In the optical pickup according to the first aspect of the present invention, the focus / tracking actuator may include any one of the plurality of first wires via a movable substrate attached to an outer surface of the objective lens holder. The current is supplied to the tracking coil and the focusing coil, and the actuator for the correction plate is connected to the movable side substrate through any one of the plurality of second wires and the remaining of the first wires. An optical pickup characterized in that a plurality of coils are energized to the coil for the correction plate.

According to a second aspect of the present invention, there is provided a base member serving as a base, an objective lens holder in which an objective lens for condensing a light beam on an optical disk is mounted, and the base member and the objective lens holder are provided. A plurality of wires that are swingably suspended between and have conductivity, and a pair of a yoke member, a magnet, a tracking coil and a focusing coil are attached to the base member,
A focus / tracking actuator that controls the objective lens integrally with the objective lens holder in a focus direction and a tracking direction of the optical disc through the plurality of wires, and is provided above the objective lens holder, and A correction plate holder in which a correction plate for transmitting the light beam from the objective lens and condensing the light beam corresponding to the tilt of the optical disc in the tilt direction on the optical disc is mounted, and the objective lens holder And a correction plate actuator that intervenes a pair of piezoelectric elements between the correction plate holder and the correction plate holder, and controls the correction plate integrally with the correction plate holder according to the tilt of the optical disc in the tilt direction. An optical pickup characterized by the following.

In the optical pickup according to the second aspect of the present invention, the focus / tracking actuator may include any one of the plurality of first wires via a movable substrate attached to an outer surface of the objective lens holder. The current is supplied to the tracking coil and the focusing coil, and the actuator for the correction plate is configured to supply electric current to the piezoelectric element with the remaining several wires of the first wire via the movable substrate. This is a characteristic optical pickup.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of an optical pickup according to the present invention will be described below in detail in the order of <first embodiment> and <second embodiment> with reference to FIGS.

<Optical Pickup of First Embodiment> FIG. 1 is a perspective view showing an optical pickup of a first embodiment according to the present invention, and FIG. 2 is a front view showing the optical pickup of the first embodiment. 3 is a plan view showing the optical pickup of the first embodiment, FIG. 4 is a rear view showing the optical pickup of the first embodiment, and FIG. 5 is an optical pickup of the first embodiment above the objective lens. FIGS. 7A and 7B are views for explaining the vicinity of the correction plate provided in FIG. 6A, FIG. 6A is a plan view of the vicinity of the correction plate, FIG. 6B is a front view thereof, FIG. It is sectional drawing which showed the concept of the optical pickup of an example.

The optical pickup 6A of the first embodiment according to the present invention shown in FIG. 1 is applicable to the optical pickup 6 in the general optical disk recording and / or reproducing apparatus described above with reference to FIG. The optical pickup 6A of the first embodiment is moved in the radial direction of the optical disk 2 by the thread motor 5 so that an information signal can be recorded on the optical disk 2 or a recorded information signal can be reproduced. ing.

In FIG. 1 to FIG. 5, a base member 52 serving as a base of the optical pickup 6A of the first embodiment includes a lower plate portion 52a having an optical path hole (not shown) for the objective lens 50 to be described later. The lower plate portion 52a is formed in a concave shape from a pair of upright portions 52b, 52b which are respectively provided upright from both left and right ends in the drawing. A pair of wire support members 53, 53 and a pair of base-side printed boards (base-side boards) 54, 54 are provided outside the pair of left and right standing portions 52b, 52b with screws 55, respectively.
Has been concluded. At this time, holes 53a are formed at four corners of the pair of left and right wire support members 53, 53, respectively.
Each of the holes 53a is filled with a damper 56 having elasticity.

A pair of left and right wire support members 53, 5
A plurality of conductive first wires 57a to 57h swing between an objective lens holder 3 and an objective lens holder 60 in which an objective lens 50 for focusing a light beam on the optical disk 2 (FIG. 11) is mounted. It is movably suspended. On this occasion,
The damper 56 is a gel-like member for damping higher-order resonance in the connection state between the wires 57a to 57h and the pair of base-side printed boards 54, 54. When the objective lens 50 is displaced in the focusing and tracking directions integrally with the objective lens holder 60 during the focusing and tracking operations by the objective lens 50, the pair of base-side printed boards 54 and 54
It is composed of a substrate made of glass epoxy or the like that can be deformed so as to compensate for the tension of a to 57h.

A pair of inner yoke members 58a, 58a are fixed to the left and right outer positions of the objective lens holder 60, and the pair of upright portions 52b, 52b are spaced apart from the pair of inner yoke members 58a, 58a. Outer yoke members 58b, 58b are fixed inside, and magnets 59, 5 are provided on opposing surfaces of each set of yoke members 58a, 58b.
9 are respectively fixed.

The objective lens holder 60 has a left-right symmetrical shape, and has an optical path hole 60 for the objective lens 50 at the center thereof.
a (FIG. 5 (c)) is formed, and the yoke / magnet holes 60b,
60b are formed. Also, the objective lens holder 60
An objective lens 50 is arranged in an optical path hole 60 a formed at the center of the inside of the lens, and is held in an objective lens holder 60. Also, the left and right yoke magnet holes 60b,
The left and right inner yoke members 58a, 58a
And magnets 59, 59 are arranged.

A pair of left and right wire support portions (60c, 60c) are provided at the center of the front and rear surfaces of the objective lens holder 60.
c) and (60c, 60c) are protrudingly provided, and a pair of front and rear wire support portions (60c, 60c), (60c, 60c) are provided.
A pair of movable-side printed boards (movable-side boards) 61, 61 are provided between 60c). The pair of wire support portions (60c, 60c), (60c, 60
In (c), two opposed wire through holes (not shown) are provided, and a space between the opposed wire through holes (not shown) is formed as a space. Further, at the regular support position of the objective lens holder 60, each wire through hole (not shown) on the objective lens holder 60 side and the base member 52
Are arranged at positions facing each other with the respective holes 53 a for wire penetration of the wire support member 53.

The above-mentioned pair of movable printed boards 61, 61 extend to above the objective lens holder 60, and have wide left and right wide portions 61a, 61a at their upper ends. Further, a pair of movable printed circuit boards 61,
Reference numeral 61 has a shape having a step, and a flexible substrate lined with, for example, glass epoxy is used in order to form the step.

Further, a total of eight conductive first wires 57a are provided.
To 57h, one end of which is inserted into each of the wire through holes of the objective lens holder 60, and the other end of which is connected to each of the wire through holes 53a of the wire support member 53 and each of the wire through holes (of the base side printed board 54). (Not shown). Both ends of each of the wires 57a to 57h are connected to the soldered portions 62b, 62b of the pair of base-side printed boards 54, 54 and the pair of movable-side printed boards 6 respectively.
1 and 61 are fixed by soldering portions 62a, 62a.

That is, the objective lens holder 60 is connected to the base member 52 by eight conductive first wires 57a to 57a.
By being connected at 7h, it is swingably supported by the base member 52. First wires 57a to 57h
In the first embodiment, a rod-shaped wire made of phosphor bronze having conductivity is used. However, for example, a plate-shaped spring material having conductivity is etched, and two or four springs are formed. It may be integrated, and it may be configured by further combining
The same applies to second wires 70a to 70d described later.

Further, focusing coils 63, 63 are fixed to the left and right upper surfaces of the objective lens holder 60, respectively, and tracking coils 64, 64 are fixed to the left and right side surfaces of the objective lens holder 60, respectively. I have.
That is, the focusing coils 63, 63, the tracking coils 64, 64, and the yoke members 58a, 58a
, Yoke members 58b, 58b, magnets 59, 5
9, a pair of left and right focus / tracking actuators 65, 65 are formed.

When the focusing coils 63, 63 are energized, the objective lens 50 is moved integrally with the objective lens holder 60 in the focusing direction of the optical disk 2 (FIG. 11) by the electromagnetic force. When the power is supplied to the objective lens 50, the objective lens 50 is moved integrally with the objective lens holder 60 in the tracking direction of the optical disk 2 (FIG. 11) by an electromagnetic force.

As shown in detail in FIGS. 5A to 5C, the left and right ends of the wide portions 61a of the pair of movable printed boards 61, 61 are provided with wire through-holes (in particular, reference numerals are attached). ) Are provided respectively. Also, the wide portions 61a, 61a of the pair of movable printed circuit boards 61, 61
U-shaped yoke members 66, 66 are fixed to the inner surfaces of the respective yoke members 66, 66, and magnets 67, 67 are fixed to the inner surfaces of the yoke members 66, 66, respectively.

The correction plate holder 68 is provided with the objective lens 5.
A pair of movable side printed circuit boards 61 attached to the objective lens holder 60 is swingably supported by second wires 70 a to 70 d above the center of the correction plate holder 68. Is formed with a hole for a correction plate (particularly without a reference numeral). A correction plate 51 which is a main part of the present invention is arranged in the hole for the correction plate, and
This correction plate 51 is located above the objective lens 50. The correction plate 51 is formed in a thin disk shape by using a transparent resin material, transmits a light beam from the objective lens 50, and emits light corresponding to the tilt of the optical disk 2 (FIG. 11) in the tilt direction. The beam is focused on the optical disc 2 as spot light.

The four conductive second wires 70a to 70a
70d has one end fixed to each of the four positions of the correction plate holder 68 by the soldering portion 69a, the other end inserted into a wire through hole (not particularly denoted by a reference numeral) of the movable printed circuit board 61, and Each of them is fixed to the movable printed circuit board 61 by the attaching portion 69b. That is, the correction plate holder 68 is provided between the pair of movable printed circuit boards 61 and 61 on the objective lens 60 side by four conductive second conductive substrates.
By being connected by the wires 70a to 70d, it is swingably supported by the objective lens holder 60.

Further, correction plate coils 71, 71 are fixed to the front and rear ends of the correction plate holder 68, and the two correction plate coils 71, 71 are constituted by one electric wire in the first embodiment. ing. The outer peripheral portion of each of the auxiliary plate coils 71, 71 is disposed in the internal space of the U-shaped yoke members 66, 66.

That is, a pair of correction plate actuators 72 are constituted by the correction plate coils 71, 71, the yoke members 66, 66, the magnets 67, 67 and the like. When the correction plate coils 71 and 71 are energized, the correction plate 51 is moved integrally with the correction plate holder 68 by electromagnetic force so as to be inclined (tilted) with respect to the optical axis direction. Thus, coma generated between the objective lens 50 and the disk 2 is corrected. When tilt correction of the optical disk 2 is performed by the correction plate 51, the inclination of the correction plate 51 is detected, for example, by obtaining reproduction signals from a plurality of photodetectors, and detecting the inclination from the plurality of reproduction signals. .

The magnetic circuits of the pair of front and rear correction plate actuators 72, 72 and the focus / tracking actuators 65, 65 are located in the horizontal direction. That is, both magnetic circuits are located in areas that do not overlap each other when viewed in a plan view, and in directions substantially orthogonal to each other.

Next, power supply means for the correction plate actuator 72 and the focus / tracking actuator 65 will be described.

As for the correction plate actuator 72, a pair of correction plate coils 71, 71 provided on the correction plate holder 68 so as to face each other are connected by wire, and one end of the correction plate coil 71 is FIG. 5 (a), (b)
As shown in (1), the first conductive pattern 73a on the correction plate holder 68, the soldering portion 69a, and the second wire 70a are electrically connected to the soldering portion 69b of the movable printed circuit board 61, and further, The movable printed board 61 is electrically connected to the base printed board 54 via the first conductive pattern 74a and the first wire 57a. On the other hand, the other end of the correction plate coil 71 is connected to the second conductive pattern 73b on the correction plate holder 68, the soldering portion 69a, the second wire 7
0b through the soldering portion 69 of the movable printed circuit board 61
b is electrically connected to the movable printed circuit board 6
The first conductive pattern 74b is electrically connected to the base-side printed board 54 via the first wire 57b.

Next, as for the focus / tracking actuator 65, one end of the focus coil 63 is connected to the third end of the movable printed circuit board 61 as shown in FIG.
It is electrically connected to the base-side printed circuit board 54 via the conductive pattern 74c, the soldering portion 62a, and the first wire 57c. On the other hand, the other end of the focusing coil 63 is connected to the fourth conductive pattern 74 d of the movable printed circuit board 61.
Next, the four ends of the tracking coil 64 are electrically connected to the base-side printed circuit board 54 via the soldering portion 62a and the first wire 57d, as shown in FIGS. The fifth to eighth conductive patterns 74e to 74h of the printed circuit board 61, the soldering portion 62a, and the first wires 57e to 57h are electrically connected to the base-side printed circuit board 54, respectively.

FIG. 6 is a conceptual sectional view of the optical pickup of the first embodiment according to the present invention. In FIG. 6, FIGS.
The description is omitted by giving the same reference numerals to the parts corresponding to the above configuration.

In the configuration of the optical pickup 6A of the first embodiment, when the focus coil 63 is energized,
The eight first wires 57 are moved by the electromagnetic force by the objective lens holder 60.
It moves in the optical axis direction against the supporting force of a to 57h, and focus control is performed by the pickup control circuit 8 (FIG. 11). When the tracking coil 64 is energized,
The eight first wires 57 are moved by the electromagnetic force by the objective lens holder 60.
It moves in a direction perpendicular to the optical axis direction against the supporting force of a to 57h, and is driven by tracking by the pickup control circuit 8 (FIG. 11).

The objective lens holder 60 is supported on the base member 52 by connecting the objective lens holder 60 and the base member 52 with eight (even number of) first conductive wires 57a to 57h. In addition, since the power supply to the focus / tracking actuator 65 is performed through any one of the first wires 57a to 57h, the first wires 57a to 57h
Can also be used as a means for supporting the objective lens holder 60 and a means for supplying power to the focus / tracking actuator 65, so that the number of components can be reduced and a simple configuration can be realized at low cost.

When the coil 71 for the correction plate is energized, the correction plate holder 68 is moved to the four second wires 70 by the electromagnetic force.
It moves in a direction inclined with respect to the optical axis direction against the supporting force of a to 70d, whereby the coma generated between the objective lens 50 and the disk 2 is corrected. That is, the optical disk 2
Although the reproduction signal is deteriorated due to the tilt of the optical axis generated between the objective lens 50 and the disk 2 due to the variation of the optical system, the processing accuracy of the turntable, or the assembly error of the optical pickup 6A, the reproduction signal is deteriorated. The coma can be canceled and corrected by tilting the correction plate 51 provided between them. The correction plate holder 68 is supported by the objective lens holder 60 by connecting four (even numbered) conductive second wires 70 a to 70 between the correction plate holder 68 and the objective lens holder 60.
d, and power is supplied to the correction plate actuator 72 by the plurality of first wires 57a.
To the second wires 70a to 70h
Since it is configured to be performed through any one of 0d,
Since the second wires 70a to 70d also serve as support means for the correction plate holder 68 and power supply means for supplying power to the correction plate actuator 72, the number of parts is small and the structure is simple.
Cost can be reduced.

The magnetic circuits of the pair of left and right focus / tracking actuators 65, 65 are respectively arranged in the left and right direction (the direction of arrow B in FIG. 3), and the first wires 57a to 57h are arranged in the same direction. In addition, since they are supported in a symmetrical number, the objective lens holder 60 is efficiently supported.

Further, the directions of the magnetic circuit of the pair of front and rear correction plate actuators 72, 72 (the arrangement direction of the yoke member 66, the magnet 67, and the correction plate coil 71) are respectively the front and rear directions (the direction of arrow A in FIG. 3). And also
The direction of the magnetic circuit of the pair of left and right focus / tracking actuators 65, 65 (the inner yoke member 58
a, the magnet 59, the outer yoke member 58b, the focusing coil 63, and the tracking coil 64 are arranged in the left-right direction (the direction of arrow B in FIG. 3), and both magnetic circuits are arranged in a direction substantially orthogonal to each other. Are located.

Here, the magnetic field generated from the magnet 59 and the tracking coil 64, which should originally be closed in the magnetic circuit, is generated as a leakage magnetic flux in the direction of the correction plate 51. The magnetic field generated from the actuator 63 is in the vertical direction as it is.
Are not affected, and the opposite relationship holds, so that mutual magnetic interference is sufficiently reduced. Further, since the correction plate actuator 72 is driven by an independent magnetic circuit, tilt correction control with stable drive sensitivity and controllability is possible regardless of the position of the objective lens holder 60 serving as a movable body in the focusing direction and the tracking direction. Become.

In addition, one of the magnets 59 (or 6
The other coil 71 (or 63, 64) does not move or vibrate due to the magnetic field generated from 7) or the magnetic field generated from one coil 63, 64 (or 71).

In the first embodiment, the first wire 5
Regarding the support intervals of 7a to 57h, those positioned vertically (first wire 57a and first wire 57e, first wire 57b and first wire 57f, first wire 57c and first wire 57c
Wire 57g, first wire 57d and first wire 57h)
Are arranged in parallel, but the spacing may be increased from the objective lens holder 60 toward the wire support member 53 of the base member 52. With this arrangement, it is possible to reduce the vibration in the tracking direction at the time of search.

<Optical Pickup of Second Embodiment> FIG. 7 is a plan view showing an optical pickup of a second embodiment according to the present invention, and FIG. 8 is a front view showing the optical pickup of the second embodiment. 9 is a diagram for explaining the vicinity of a correction plate provided above an objective lens in the optical pickup of the second embodiment, (a) is a plan view near the correction plate, (b) is a front view thereof, FIG. 10C is a right side view thereof, and FIG. 10 is a sectional view showing the concept of the optical pickup of the second embodiment.

7 to 9, the same components as those in the first embodiment described above in the second embodiment are denoted by the same reference numerals in the drawings, and description thereof will be omitted. Only different portions will be described.

The optical pickup 6B according to the second embodiment of the present invention shown in FIG. 7 is also applicable to the optical pickup 6 in the general optical disk recording and / or reproducing apparatus described with reference to FIG. The optical pickup 6B of the second embodiment can be used to record information signals on the optical disc 2 (FIG. 11) and to reproduce recorded information signals.

That is, in FIG. 7 to FIG. 9, the support of the correction plate holder 68 having the correction plate 51 mounted therein to the objective lens holder 60 is not the second wire but the correction plate holder 68 and the objective lens holder 60 side. A pair of front and rear piezoelectric elements 75 and 7 interposed between the movable printed circuit board 61
5 is performed. The pair of piezoelectric elements 75, 75 are made of, for example, piezoelectric ceramics that extend in the optical axis direction when a voltage is applied. That is, in the second embodiment, the correction plate actuator 72 is formed by the pair of piezoelectric elements 75,75.
Is configured. At this time, the pair of piezoelectric elements 75, 75
Has one end fixed to the objective lens holder 60 and the other end fixed to the correction plate holder 68.

For the piezoelectric ceramics, for example, thin PZT (lead zirconate titanate: ceramics of electronic engineering) is laminated, and an electrode section is interposed between each PZT layer. It is configured by alternately connecting every other electrode, with one being a positive electrode and the other being a negative electrode.

One piezoelectric element 75 is supplied with electric power by the first conductive patterns 74a, 74b
The first piezoelectric elements 75 are supplied with power via the first wires 57 a and 57 h via the first printed circuit board 61.
The first wire 57 is connected via the conductive patterns 74c and 74d.
c, 57d, and each of the piezoelectric elements 75, 75 is configured to be independently controllable.

FIG. 10 is a conceptual sectional view of an optical pickup according to a second embodiment of the present invention. In FIG. 10, FIG.
The same reference numerals are given to the portions corresponding to the configuration shown in FIG. 9 and the description thereof will be omitted.

In the above configuration, a pair of piezoelectric elements 75,
The tilt of the correction plate 51 can be adjusted because the inclination of the correction plate 51 can be changed by supplying voltages of different levels to the voltage 75. The inclination of the correction plate 51 is detected, for example, so as to obtain reproduction signals from a plurality of photodetectors, and the inclination is detected from the plurality of reproduction signals.

In the second embodiment, a pair of piezoelectric elements 7
Since the auxiliary lens actuators 72 are constituted by 5, 75, there is also an advantage that there is no mutual magnetic interference with the focus / tracking actuator 65.

[0065]

According to the optical pickup according to the present invention described in detail above, according to the first and second aspects, the correction plate provided above the objective lens is swingably supported with respect to the objective lens holder. Since the light beam from the objective lens is transmitted by the correction plate and the light beam corresponding to the tilt in the tilt direction of the optical disk can be condensed on the optical disk, the tilt of the optical pickup as in the conventional case can be corrected by tilting the entire optical pickup. Tilt correction control with more stable drive sensitivity and controllability than the control method can be performed, and the tilt correction control structure can be provided at a low cost with a small number of parts and a simple structure. Further, the focus / tracking control on the optical disk by the objective lens and the tilt correction control on the optical disk by the correction plate can be independently performed. Further, when the objective lens holder is swingably supported by the plurality of first wires and the correction plate holder is swingably supported by the plurality of second wires, any one of the plurality of first wires may be used. The tracking coil and the focusing coil constituting the focus / tracking actuator are energized by several wires, and the correction plate actuator is operated by any one of the plurality of second wires and the remaining several first wires. Since the current supply to the coil for the compensating plate is performed, each of the first and second wires effectively has a support function and a current supply function, thereby contributing to a reduction in the number of components.

According to the third and fourth aspects, even when a pair of piezoelectric elements are used for the correction plate actuator, substantially the same effects as in the first and second aspects can be obtained.

[Brief description of the drawings]

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

FIG. 2 is a front view showing the optical pickup of the first embodiment according to the present invention.

FIG. 3 is a plan view showing the optical pickup of the first embodiment according to the present invention.

FIG. 4 is a rear view showing the optical pickup of the first embodiment according to the present invention.

5A and 5B are diagrams for explaining the vicinity of a correction plate provided above an objective lens in the optical pickup according to the first embodiment of the present invention, wherein FIG. 5A is a plan view of the vicinity of the correction plate, and FIG.
Is a front view thereof, and (c) is a right side view thereof.

FIG. 6 is a sectional view showing the concept of the optical pickup of the first embodiment according to the present invention.

FIG. 7 is a plan view showing an optical pickup of a second embodiment according to the present invention.

FIG. 8 is a front view showing an optical pickup of a second embodiment according to the present invention.

9A and 9B are diagrams for explaining the vicinity of a correction plate provided above an objective lens in the optical pickup according to the second embodiment of the present invention, wherein FIG. 9A is a plan view of the vicinity of the correction plate, and FIG.
Is a front view thereof, and (c) is a right side view thereof.

FIG. 10 is a sectional view showing the concept of an optical pickup according to a second embodiment of the present invention.

FIG. 11 is a block diagram of a general optical disk recording and / or reproducing apparatus.

[Explanation of symbols]

2 optical disk, 6A optical pickup of the first embodiment,
6B: optical pickup of the second embodiment, 50: objective lens, 51: correction plate, 52: base member, 54: pair of base-side printed boards (base-side boards), 57a to 57h
... First wire, 58a ... Inner yoke member, 58b ... Outer yoke member, 59 ... Magnet, 60 ... Objective lens holder, 61 ... Movable printed circuit board (movable board), 63 ...
Focusing coil, 64 ... Tracking coil, 6
5. Focus / tracking actuator, 66
... Yoke member, 67 ... magnet, 68 ... correction plate holder, 70a to 70d ... second wire, 71 ... correction plate coil, 72 ... correction plate actuator, 75 ... piezoelectric element.

Claims (4)

[Claims] 1. A base member serving as a base, an objective lens holder having an objective lens inside for condensing a light beam on an optical disk, and swingable between the base member and the objective lens holder. A plurality of first wires suspended in the base member, and a pair of a yoke member, a magnet, a tracking coil and a focusing coil mounted in the base member, respectively, and the objective lens is integrated with the objective lens holder. A focus / tracking actuator that controls the focus direction and the tracking direction of the optical disc via the plurality of first wires; and the light beam from the objective lens, which is provided above the objective lens holder. And transmits the light beam corresponding to the tilt of the optical disc in the tilt direction to the optical disc. A correction plate holder in which a correction plate for converging light is internally mounted; a plurality of conductive second wires suspended swingably between the objective lens holder and the correction plate holder; A pair of a yoke member, a magnet, and a coil for a correction plate are respectively mounted in the objective lens holder, and the correction plate is integrally formed with the correction plate holder via the plurality of second wires in a tilt direction of the optical disk. An optical pickup, comprising: a correction plate actuator controlled according to the inclination. 2. The optical pickup according to claim 1, wherein the focus / tracking actuator includes any one of the plurality of first wires via a movable-side substrate attached to an outer surface of the objective lens holder. The energizing of the tracking coil and the focusing coil is performed by the actuator for the correction plate, and the actuator for the correction plate includes any one of the plurality of second wires and the remaining number of the first wires via the movable substrate. An optical pickup characterized in that electricity is supplied to the coil for the correction plate with a book. 3. A base member serving as a base, an objective lens holder in which an objective lens for condensing a light beam on an optical disk is mounted, and swingable between the base member and the objective lens holder. A plurality of wires having conductivity, and a pair of a yoke member, a magnet, a tracking coil and a focusing coil are respectively mounted in the base member, and the objective lens is integrated with the objective lens holder. A focus / tracking actuator for controlling a focus direction and a tracking direction of the optical disc through the plurality of wires; provided above the objective lens holder, and transmitting the light beam from the objective lens The light beam corresponding to the tilt of the optical disc in the tilt direction is focused on the optical disc. A correction plate holder in which a correction plate for mounting the correction plate is mounted; a pair of piezoelectric elements interposed between the objective lens holder and the correction plate holder; An optical pickup, comprising: a correction plate actuator that is controlled in accordance with the tilt of the optical pickup in the tilt direction. 4. The optical pickup according to claim 3, wherein the focus / tracking actuator includes any one of the plurality of first wires via a movable-side substrate attached to an outer surface of the objective lens holder. And energizing the tracking coil and the focusing coil, and the correction plate actuator energizing the piezoelectric element with the remaining few of the first wires via the movable-side substrate. Optical pickup.