JP2009295239A - Optical pickup and optical disk device - Google Patents

Abstract

An optical pickup and an optical disk apparatus are provided that are advantageous in reducing the size and the degree of freedom of design.
A base 40 has an upper surface 40A located on one side in the thickness direction and a lower surface 40B located on the other side in the thickness direction. The support block 46 is supported on the upper surface 40 </ b> A of the base 40. The fixing plate 48 is integrally coupled to the support block 46 and attached to the base 40. The fixing plate 48 has a main body plate portion 56 and a fixing plate portion 58. The main body plate portion 56 is attached to the upper surface 46 </ b> A of the support block 46. The fixed plate portion 58 is an edge portion located on both sides in the width direction of the main body plate portion 56 and protrudes from an intermediate position in the length direction of the edge portion toward the upper surface 40A of the base 40, and the fixed plate portion The front end of 58 is directly attached to the upper surface 40A of the base 40 or attached to the base 40 via the yoke 41.
[Selection] Figure 3

Description

  The present invention relates to an optical pickup that records and reproduces signals on an optical disc and an optical disc apparatus having such an optical pickup.

There is an optical pickup for recording or reproducing a signal or recording and reproducing an optical disk such as a DVD (Digital Versatile Disk).
Such an optical pickup connects a base, a lens holder for holding an objective lens, a support block supported on the upper surface of the base, and the lens holder and the support block, and moves the lens holder relative to the support block. Suspension wires that can be supported, a coil provided on the lens holder, and a magnetic field generator disposed above the upper surface of the base and facing the coil with a space therebetween ( Patent Document 1).
By the way, when assembling such an optical pickup, it is necessary to adjust the position of the support block with respect to the base.
Therefore, conventionally, the fixing block is integrally coupled to the lower surface of the support block facing the base, and the position of the support block is adjusted with respect to the base while the fixing plate is held by an adjustment jig. When the above is completed, the fixing plate is attached to the upper surface of the base by adhesive bonding or soldering.
JP 2006-31864 A

However, in the above prior art, since the fixing plate is attached to the upper surface of the base, notches and openings for jigs are provided in the base so that the jig holding the fixing plate does not interfere with the base. There is a need.
Such notches and openings are dead spaces, which is disadvantageous for downsizing and freedom of design.
The present invention has been made in view of such circumstances, and an object thereof is to provide an optical pickup and an optical disc apparatus that are advantageous in reducing the size and the degree of design freedom.

In order to achieve the above object, an optical pickup according to the present invention includes a base, a lens holder for holding an objective lens, a support block supported on the upper surface of the base, and the support block integrated with the support block. A fixing plate attached to a base, a suspension wire that connects the lens holder and the support block and supports the lens holder above the upper surface of the base, a coil provided on the lens holder, A magnetic field generator disposed above the upper surface of the base and facing the coil in a direction perpendicular to the optical axis of the objective lens with a gap therebetween, and the fixing plate includes A main body plate portion attached to a surface opposite to the surface facing the upper surface of the base, and a support block protruding from the main body plate portion toward the upper surface of the base And a fixing plate portion which is attached to the serial-based top.
The optical disc apparatus according to the present invention includes a driving unit that holds and rotates the optical disc, and a recording and / or reproducing light beam that is applied to the optical disc that is rotationally driven by the driving unit, and is reflected by the optical disc. An optical pickup for detecting a light beam, the optical pickup comprising a base, a lens holder for holding an objective lens, a support block supported on an upper surface of the base, and an integral part of the support block A fixing plate coupled to and attached to the base, a suspension wire that connects the lens holder and the support block and supports the lens holder above the upper surface of the base, and a coil provided on the lens holder And the coil in a direction perpendicular to the optical axis of the objective lens disposed above the upper surface of the base. A magnetic field generator provided to face each other with a gap therebetween, and the fixing plate is attached to a surface opposite to the surface on which the support block faces the upper surface of the base; And a fixed plate portion projecting from the main body plate portion toward the upper surface of the base and attached to the upper surface of the base.

According to the present invention, the main body plate portion to be attached to the support block is disposed at a position separated from the base, and the adjustment jig for holding the fixing plate does not interfere with the base, so that it is conventionally necessary. There is no need to provide notches and openings for jigs in the base.
Therefore, since members and parts can be arranged in a portion that has conventionally been a dead space due to a notch or an opening, it is advantageous in reducing the size of the optical pickup and the optical disc apparatus and ensuring the degree of design freedom. Become.

(Optical disk device 100)
Next, an embodiment of the present invention will be described.
First, an optical disc apparatus incorporating the optical pickup of the present invention will be described.
FIG. 1 is a block diagram showing a configuration of an optical disc apparatus 100 in which an optical pickup 10 according to the present embodiment is incorporated.
As shown in FIG. 1, an optical disk apparatus 100 includes a spindle motor 12 as a driving means for rotating the optical disk 2, an optical pickup 10, a feed motor 16 as a driving means for moving the optical pickup 10 in the radial direction, and the like. It is configured to include.
Here, the spindle motor 12 is configured to be driven and controlled at a predetermined rotational speed by the system controller 18 and the servo control unit 20.

The optical pickup 10 irradiates the signal recording surface of the optical disc 2 rotating according to instructions from the system controller 18 and the servo control unit 20 with a light beam. Recording and / or reproduction of an optical signal with respect to the optical disc 2 is performed by such light irradiation.
The optical pickup 10 is configured to detect various light beams based on the reflected light beam from the signal recording surface of the optical disc 2 and to supply a signal corresponding to each light beam to the signal processing unit 24. Yes.
The signal modulation / demodulation unit and ECC block 22 modulate and demodulate the signal output from the signal processing unit 24 and add an ECC (error correction code).

The signal processing unit 24 is a servo control signal based on a detection signal corresponding to each light beam, that is, a focus error signal, a tracking error signal, an RF signal, a monitor signal (R-OPC signal) necessary for running OPC processing, The ATIP signal and the like necessary for controlling the rotation of the optical disc during recording can be generated.
Various conventionally known methods can be employed as a method for generating a focus error signal, a tracking error signal, and an RF signal by the optical pickup 10.
Further, predetermined processing such as demodulation and error correction processing based on these signals is performed by the servo control unit 20, the signal modulation unit, the ECC block 22, and the like according to the type of recording medium to be reproduced.
Here, if the recording signal demodulated by the signal modulation unit and the ECC block 22 is for data storage of a computer, for example, it is sent to an external computer 28 or the like via the interface 26. Accordingly, the external computer 28 and the like are configured to receive a signal recorded on the optical disc 2 as a reproduction signal.

If the recording signal demodulated by the signal modulation unit and the ECC block 22 is for audio / visual use, the digital / analog conversion is performed by the D / A conversion unit of the D / A and A / D converter 30, and the audio / visual conversion is performed. It is supplied to the processing unit 32. The audio / video processing unit 32 performs audio / video signal processing and transmits the audio / video signal to an external imaging / projection device via the audio / visual signal input / output unit 34.
A feed motor 16 is connected to the optical pickup 10, and the optical pickup 10 is moved to a predetermined recording track on the optical disc 2 by the rotation of the feed motor 16.
The servo control unit 20 controls the focusing direction and tracking direction of the objective lens (not shown) of the optical pickup 10 based on the focus error signal and the tracking error signal in addition to the control of the spindle motor 12 and the feed motor 16. Further, radial skew is controlled.
The laser control unit 36 controls the laser light source of the optical pickup 10.

(Optical pickup 10)
Next, the optical pickup 10 of the present embodiment will be described.
FIG. 2 is a plan view showing the configuration of the optical pickup 10, and FIG. 3 is an assembly explanatory diagram of the optical pickup 10.
As shown in FIGS. 2 and 3, the optical pickup 10 includes a base 40, a yoke 41, an objective lens 42, a lens holder 44, a support block 46, a fixing plate 48, a suspension wire 50, a coil. 52, a magnetic field generator 54, a light source (not shown), a light detection element, and the like disposed below the base 40.
In the present invention, the focus direction Z refers to the thickness direction of the optical disc 2, in other words, the optical axis direction of the objective lens 42. The tracking direction X refers to the radial direction of the optical disc 2. The tangential direction (tangential direction) Y is a tangential direction of the circumference of the optical disc 2, that is, a direction orthogonal to both the focus direction Z and the tracking direction X.

The base 40 has a thin plate shape having a width along the tracking direction X, a length along the tangential direction Y, and a thickness along the focus direction Z.
The base 40 has an upper surface 40A located on one side in the thickness direction and a lower surface 40B located on the other side in the thickness direction.

The objective lens 42 is held by a lens holder 44.
The objective lens 42 irradiates the optical disk 2 with a recording and / or reproducing light beam emitted from the light source, and guides the reflected light beam reflected by the optical disk to the light detection element.

The support block 46 is supported by the upper surface 40 </ b> A of the base 40, and is disposed at a distance from the lens holder 44 in the tangential direction Y.
In the present embodiment, the support block 46 is disposed at the end of the base 40 in the tangential direction Y.
The support block 46 has a lower surface 46B facing the upper surface 40A of the base 40 and an upper surface 46A located on the opposite side of the lower surface 46B.

The fixing plate 48 is integrally coupled to the support block 46 and attached to the base 40.
In the present embodiment, the fixing plate 48 is made of metal and is formed of a magnetic material that is attracted by a magnet.
The fixing plate 48 has a main body plate portion 56 and a fixing plate portion 58 and is made of sheet metal.
The main body plate portion 56 has a thin plate shape having a width, a length, and a thickness along the width, length, and thickness of the base 40, respectively.
A plurality of screw insertion holes 5602 are formed penetratingly at a position closer to one side in the length direction of the main body plate portion 56.
A plurality of engagement holes 5604 through which pins of an adjustment jig, which will be described later, are inserted are formed through the portion of the main body plate portion 56 on the other side in the length direction.
The main body plate portion 56 is attached to the upper surface 46 </ b> A of the support block 46.
In the present embodiment, screws (not shown) are inserted into the screw insertion holes 5602 and fastened to the upper surface 56A of the support block 46, whereby the main body plate portion 56 is attached to the upper surface 46A of the support block 46.
The fixed plate portion 58 is an edge portion located on both sides in the width direction of the main body plate portion 56 and protrudes from an intermediate position in the length direction of the edge portion toward the upper surface 40A of the base 40, and the fixed plate portion The front part of 58 is attached to the upper surface 40 </ b> A of the base 40.
The fixing plate portion 58 is attached to the base 40 by adhesion using an adhesive or by soldering.
In a state where the fixing plate 48 is attached to the base 40, the main body plate portion 56 extends in parallel with the upper surface 40 </ b> A of the base 40.
Note that the fixed plate portion 58 is not directly attached to the base 40 as in the present embodiment, but the fixed plate portion 58 is attached to the yoke 41 so that the fixed plate portion 58 is interposed via the yoke 41. Of course, it may be attached to the base 40.
In particular, when the base 40 is formed of a synthetic resin material for weight reduction and cost reduction, the fixing plate portion 58 cannot be soldered to the base 40, and the fixing plate portion 58 and the base 40 are not soldered. It is necessary to avoid adhering the fixing plate portion 58 to the base 40 with an adhesive in consideration of the change with time due to the difference in the linear expansion coefficient.
In such a case, it is preferable to attach the fixing plate portion 58 to the base 40 via the yoke 41. The fixing plate portion 58 is attached to the yoke 41 by adhesion using an adhesive or by soldering.
In order to attach the fixed plate portion 58 to the yoke 41, it is preferable to provide the yoke 41 with a shape for attaching the fixed plate portion 58.

The lens holder 44 is supported by the tip of the suspension wire 50 protruding from the support block 46.
The magnetic field generators 54 are disposed on both sides of the lens holder 44 in the tangential direction Y.

The base portions of the suspension wires 50 are respectively attached to the two positions spaced in the focus direction Z at both ends in the width direction of the support block 46.
The tip portions of the suspension wires 50 are attached to the two ends of the lens holder 44 in the tracking direction X at intervals in the focus direction Z, and the lens holder 44 is placed on the support block 46 via the suspension wire 50 in the tracking direction. It is supported so as to be movable in X and focus direction Z.
The coils 52 are respectively attached at two positions spaced in the tracking direction X at both ends of the lens holder 44 in the tangential direction Y.

The yoke 41 is mounted on the base 40, and the yoke 41 includes a substrate portion 4102 that extends in the tangential direction Y below the lens holder 44, and standing portions 4104 that stand up from both ends of the substrate portion 4102.
The magnets 60 are attached to the upright portions 4104, so that the magnets 60 face both ends of the lens holder 44 in the tangential direction Y.
In the present embodiment, the magnetic field generation unit 54 is configured by a standing part 4104 and a magnet 60.
In other words, the magnetic field generator 54 is disposed above the upper surface 40A of the base 40 and is provided to face the coil 52 with a space in a direction orthogonal to the optical axis.

  Since a light source and a light detection element are disposed below the base 40, openings 4010 and 4110 for guiding light from the light source to the objective lens 42 are formed in the base 40 and the substrate portion 4102 of the yoke 41, respectively. Has been.

Then, by supplying a drive signal to the coil 52, the lens holder 44 is moved in the tracking direction X or the focus direction Z by the magnetic interaction between the magnetic field generated by the coil 52 and the magnetic field generated by the magnetic field generator 54. As a result, the light spot formed by the reproducing or recording light beam formed by the objective lens 42 accurately follows the track of the optical disc 2.
Therefore, in the present embodiment, a so-called biaxial actuator is configured by the coil 52, the magnetic field generator 54, the suspension wire 50, and the like.

(assembly)
Next, the assembly will be described with reference to FIGS. 2 and 3. In FIG. 3, the yoke 41 and the magnet 60 are omitted for convenience of description.
First, as shown in FIG. 2, the yoke 41 with the magnet 60 attached thereto is attached to the base 40 with screws N, the yoke 41 is fixed on the base 40, and the base 40 is used as a first jig (not shown). Fix it.
Further, the fixing plate 48 is attached to the support block 46 by screwing the screw inserted through the screw insertion hole 5602 of the fixing plate 48 into the support block 46.

Next, the fixing plate 48 is held by the second jig 80.
In the present embodiment, the second jig 80 includes an upper clamp 82 and a lower clamp 84.
The upper clamp 82 is provided with an electromagnet 86 having an abutting surface 86 formed of a flat surface capable of coming into contact with the surface of the main body plate portion 56 of the fixing plate 48, and the fixing plate 48 protruding from the abutting surface 86. And a plurality of pins 88 that can be engaged with the engagement holes 5604.
The lower clamp 84 has an abutting piece 90 that is provided so as to be movable in a direction in which the lower clamp 84 moves toward and away from the abutting surface 86. In this embodiment, the abutting piece 90 is configured by a leaf spring. Yes.

That is, the holding plate 48 is held by the second jig 80 as follows.
Each pin 88 of the upper clamp 82 is inserted into the engagement hole 5604 from above the fixing plate 48 and the electromagnet 86 is operated to attract the fixing plate 48 to the abutting surface 86.
Next, the abutting piece 90 of the lower clamp 84 is elastically brought into contact with the lower surface of the fixing plate 48, thereby sandwiching the main body plate portion 56 between the abutting piece 90 and the abutting surface 86.
As a result, the fixing plate 48 is held by the second jig 80.
Although the lower clamp 84 may be omitted, the provision of the lower clamp 84 as in the present embodiment is advantageous in stably holding the fixing plate 48 by the second jig 80. .
In this state, in the tangential direction Y on the base 40, the tip portions of the magnets 60 face the tip portions of the coils 52 at both ends in the tangential direction Y of the lens holder 44.

Next, a light beam emitted from a light source located below the base 40 and converged by the objective lens 52 is imaged by an imaging device such as a video camera, and the captured image is displayed on the display. The position of the fixing plate 48 is adjusted by moving the second jig 80 so that the position of the light beam is at a predetermined position.
For example, the second jig 80 may be a tracking direction X, a tangential direction Y, a focus direction Z, a rotation direction having an axis extending in the tracking direction X as a central axis, and an axis extending in the tangential direction Y. Adjustment is made in six rotational directions, with the rotational direction as the central axis and the rotational direction with the axis extending in the focus direction Z as the central axis.
In this way, if the position of the light beam converged by the objective lens 52 is located at a predetermined position on the display screen, in other words, the relative positions of the magnet 60 and the coil 52 are adjusted, and the position relative to the base 40 is adjusted. When the position adjustment of the support block 46 is completed, the tip of the attachment piece 58 of the fixing plate 48 and the upper surface 40A of the base 40 are fixed by bonding with an adhesive or soldering.
Finally, the first jig and the second jig are removed, and the assembly of the optical pickup 10 is completed.
Note that the method of adjusting the position of the support block 46 with respect to the base 40 is not limited to the method described above, and various conventionally known position adjustment methods can be employed.

As described above, according to the present embodiment, the fixing plate 48 includes the main body plate portion 56 attached to the surface 46A opposite to the surface where the support block 46 faces the upper surface 40A of the base 40, and the main body plate. And a fixing plate portion 58 projecting from the portion 56 toward the upper surface 40A of the base 40 and attached to the upper surface 40A of the base 40.
Therefore, the main body plate portion 56 attached to the support block 46 is disposed at a location away from the upper surface 40A of the base 40, and the adjustment jig that holds the fixing plate 48 does not interfere with the base 40. Therefore, it is not necessary to provide the base 40 with a notch or opening for a jig, which was necessary in the past.
Therefore, since members and parts can be arranged in a portion that has conventionally been a dead space due to a notch or an opening, it is advantageous in reducing the size of the optical pickup 10 and thus the optical disc apparatus 100.
Further, since the members and parts can be arranged in the portion of the base 40 that has become a dead space due to the notches and openings, it is possible to secure a bonding space for bonding the members and parts, or positions of the members and parts. An adjustment space for adjustment can be secured, or a margin of an arrangement path of an optical path constituted by optical parts can be secured, so that the quality of the optical pickup 10 can be improved while ensuring the degree of design freedom of the optical pickup 10. It is advantageous in planning.
Further, since notches and openings are not provided in the base 40, it is advantageous in improving the mechanical strength and rigidity of the base 40.

Next, it demonstrates in comparison with a comparative example.
FIG. 4 is an assembly explanatory view of an optical pickup of a comparative example. The same or corresponding parts and members as those of the embodiment are denoted by the same reference numerals and description thereof is omitted.
As shown in FIG. 4, in the optical pickup of the comparative example, the main body plate portion 56 of the fixing plate 48 is attached to the upper surface 40 </ b> A of the base 40.
The base 40 is provided with an opening 4020 for avoiding interference with the lower clamp 94 of the second jig 92.
The second jig 92 includes a lower clamp 94 and an upper clamp 96.
The lower clamp 94 includes a shaft portion 9402, a contact surface 9404 formed at the upper end of the shaft portion 9402, and a plurality of pins 9406 that protrude from the contact surface 9404.
The upper clamp 96 has an abutting surface 9602 that is provided so as to be movable in a direction in which the upper clamp 96 moves toward and away from the abutting surface 9404.
The fixing plate 48 is held by the second jig 92 as follows.
The shaft portion 9402 of the lower clamp 94 is inserted from below the opening 4020 of the base 40, and a plurality of pins 9406 are inserted from below the fixing plate 48 into the engagement holes 5604, and the abutting surface 9602 of the upper clamp 96 is fixed. The main body plate portion 56 is sandwiched between the abutting surface 9602 and the abutting surface 9404 by being abutted against the upper surface of the plate 48.
As a result, the fixing plate 48 is held by the second jig 80.

Therefore, in the comparative example, since the main body plate portion 56 of the fixing plate 48 is attached to the upper surface 40A of the base 40, the base 40 must be provided with the opening 4020 for the second jig. 40 becomes larger by the size of the opening 4020, which is disadvantageous in reducing the size of the optical pickup 10 and hence the optical disc apparatus 100.
In addition, since the base 40 must be provided with the opening 4020 for the second jig, the base 40 is constituted by an adhesive space for bonding the member and the component, an adjustment space for adjusting the position of the member and the component, and an optical component. This is disadvantageous in securing a margin for the arrangement space of the optical path, and it is difficult to ensure the degree of freedom in designing the optical pickup 10, which is also disadvantageous in improving the quality of the optical pickup 10.
Moreover, since the opening 4020 for the second jig must be provided in the base 40, it is disadvantageous in improving the mechanical strength and rigidity of the base 40.
In contrast to such a comparative example, the present embodiment does not require a notch or opening for jigs to be provided in the base 40, and a member or component in a portion that has become a dead space by a conventional notch or opening. Therefore, it is extremely advantageous for reducing the size of the optical pickup 10, improving the design freedom, improving the quality, and improving the mechanical strength and rigidity of the base 40.
In the present embodiment, the case where there is one objective lens 42 has been described. However, two objective lenses such as a DVD and CD objective lens and a Blu-ray objective lens, or three or more objective lenses are used. Of course, the present invention is also applied to an optical pickup having the above.

1 is a block diagram showing a configuration of an optical disc apparatus 100 in which an optical pickup 10 according to the present embodiment is incorporated. 1 is a plan view showing a configuration of an optical pickup 10. FIG. 3 is an assembly explanatory diagram of the optical pickup 10. It is assembly explanatory drawing of the optical pick-up of a comparative example.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Optical pick-up, 40 ... Base, 42 ... Objective lens, 44 ... Lens holder, 46 ... Support block, 48 ... Fixing plate, 50 ... Suspension wire, 52 ... Coil, 54 ... Magnetic field generating part, 56 ... Main body plate part, 58 ... Fixed plate part, 100 ... Optical disk device.

Claims (7)

Base,
A lens holder for holding the objective lens;
A support block supported on the upper surface of the base;
A fixing plate integrally coupled to the support block and attached to the base;
A suspension wire that connects the lens holder and the support block and supports the lens holder above the upper surface of the base;
A coil provided in the lens holder;
A magnetic field generator disposed above the upper surface of the base and provided to face the coil with a gap in a direction perpendicular to the optical axis of the objective lens;
The fixing plate is
A main body plate portion attached to a surface opposite to the surface facing the upper surface of the base;
A fixed plate portion protruding from the main body plate portion toward the upper surface of the base and attached to the upper surface of the base;
Optical pickup. The support block is disposed at a distance from the lens holder in a tangential direction orthogonal to a focus direction that is an optical axis direction of the objective lens.
The optical pickup according to claim 1. The suspension wire supports the lens holder so that the lens holder can move in the focus direction and the tracking direction perpendicular to the focus direction and the tangential direction with respect to the support block.
The optical pickup according to claim 1. The main body plate portion extends in parallel with the upper surface of the base.
The optical pickup according to claim 1. The fixing plate part is attached to the base by bonding using an adhesive or by soldering.
The optical pickup according to claim 1. The fixing plate is made of a magnetic material attracted by a magnet.
The optical pickup according to claim 1. Driving means for holding and rotating the optical disc;
An optical pickup that irradiates a recording and / or reproducing light beam to the optical disk that is rotationally driven by the driving means, and detects a reflected light beam reflected by the optical disk;
The optical pickup is
Base,
A lens holder for holding the objective lens;
A support block supported on the upper surface of the base;
A fixing plate integrally coupled to the support block and attached to the base;
A suspension wire that connects the lens holder and the support block and supports the lens holder above the upper surface of the base;
A coil provided in the lens holder;
A magnetic field generator disposed above the upper surface of the base and provided to face the coil with a gap in a direction perpendicular to the optical axis of the objective lens;
The fixing plate is
A main body plate portion attached to a surface opposite to the surface facing the upper surface of the base;
A fixed plate portion protruding from the main body plate portion toward the upper surface of the base and attached to the upper surface of the base;
Optical disk device.

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