JP3318061B2 - Optical disk drive - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk apparatus for reproducing or recording / reproducing data from a recording medium such as a CD-ROM (compact disk-read only memory) or magneto-optical or phase change.

[0002]

2. Description of the Related Art In recent years, there has been an increasing tendency for optical disk devices to be smaller and thinner and to have higher performance so that they can be mounted on small information devices such as portable devices. Hereinafter, a conventional optical disk device will be described. FIG. 10 is an external view of a main part of a conventional optical disk device, and FIG. 11 is an external view of a pickup head of the conventional optical disk device. As shown in FIG. 10, the optical disc apparatus includes an optical disc 1 as a recording medium and a spindle motor 2 for rotating the optical disc 1.
And a fixed optical section 3 and a moving optical section 4 for reproducing or recording / reproducing data on the optical disc 1, and a feed section 5 for moving the moving optical section 4 in the radial direction of the optical disc 1. I have. Fixed optical part 3
A laser emitting means for irradiating the optical disc 1 with laser light, a light detecting unit for detecting return light from the optical disc 1 and optical components, and the like. An optical component for guiding and condensing the laser beam from the unit 3 to the optical disc 1 and focusing driving means and tracking driving means are provided. In FIG. 11, reference numeral 6 denotes an objective lens for condensing the laser light emitted from the fixed optical unit 3 on the optical disk 1, and 7 denotes a bobbin for holding the objective lens 6. Reference numerals 8 and 9 denote a focus coil and a tracking coil provided on the bobbin 7, respectively. The focus coil 8 is wound around the bobbin 7, and the tracking coil 9 is fixed to the focus coil 8 by bonding or the like. Reference numeral 10 denotes a suspension spring for elastically supporting the bobbin 7, and a head base 11 and the bobbin 7
The bobbin 7 is moved in the focus direction (arrow A direction) and the tracking direction with respect to the head base 11.
(In the direction of arrow B). Reference numeral 12 denotes a pair of magnets fixed to the head base 11 so as to face the focus coil 8 and the tracking coil 9. The pickup head shown in FIG. 11 is mounted on the carriage base 13 of FIG. 10, and a plurality of guide rollers 14 provided on the carriage base 13 abut on two guide shafts 15, and the carriage base 13 is 1 is slidable in the radial direction. Reference numeral 16 denotes a feed magnet, which is fixed to a back yoke 17 made of a ferromagnetic material. Reference numeral 18 denotes an opposing yoke made of a ferromagnetic material provided so as to oppose the feed magnet 16 in the radial direction of the optical disc 1. The feed magnet 16, the back yoke 17 and the opposing yoke 18 constitute a magnetic circuit of the feed section 5. The carriage base 13 is provided with a pair of feed coils 19, and the opposing yoke 18 is provided so as to penetrate the feed coil 19.

The operation of the optical disk apparatus configured as described above will be described below. The laser light emitted from the fixed optical unit 3 is a head base 11 serving as the movable optical unit 4.
The light is guided to the objective lens 6 by a start-up mirror (not shown) provided on the optical disk 1, and is focused on the optical disk 1 by the objective lens 6. The reflected light from the optical disk 1 passes through the objective lens 6 and the rising mirror, and is guided to a light detecting unit (not shown) provided in the fixed optical unit 3, so that the data recorded on the optical disk 1 is Playback can be performed. In order to reproduce the recorded data of the optical disc 1 satisfactorily, the objective lens 6 must be moved in the focusing direction (the direction of arrow A) and the tracking direction.
(In the direction of arrow B) to optimally focus the laser beam on the optical disc 1. The objective lens 6 is driven to focus against the suspension spring 10 by the electromagnetic action of the focus coil 8 and the magnet 12 in the focus direction, and is similarly driven by the electromagnetic action of the tracking coil 9 and the magnet 12 in the tracking direction. . In addition, the carriage base 13 moves along the guide shaft 15 by the electromagnetic action of the feed coil 19 and the feed magnet 16 provided on the carriage base 13. By driving the carriage base 13, the objective lens 6 is driven for feed. By this feed drive, the objective lens 6 can move over the entire data area of the optical disc 1. By the focusing drive, the tracking drive, and the feed drive, the objective lens 6 is focused so that the laser beam is optimally focused on a desired position in the data area of the optical disc 1.
Is driven.

[0004]

However, in the above-described conventional configuration, since the fixed optical unit 3 and the movable optical unit 4 are separated, it is necessary to ensure optical positional accuracy in the moving range of the carriage base 13. There is a problem that it is necessary to improve the accuracy of parts and to perform high-precision assembly adjustment. Also, in order to drive in the tracking direction, a tracking drive unit (tracking coil 9 and magnet 12) and a feed drive unit (feed coil 19 and Magnets 16) are required, and it is difficult to reduce the size and cost due to the increase in the number of parts. In addition, since the focus coil 8 and the tracking coil 9 are overlapped in the magnetic circuit using the magnet 12, the effective portions of the respective coils are the same. Larger gaps in the magnetic circuit than on the surface reduce magnetic efficiency, that is, actuator efficiency There is a problem in that that.
SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems, and an object of the present invention is to provide a small, inexpensive, and highly reliable optical disk device that can easily ensure optical position accuracy.

[0005]

In order to achieve the above object, the present invention provides an optical disk apparatus which emits laser light and detects reflected light, and condenses the laser light on an optical disk. An objective lens, a bobbin for holding the laser unit and the objective lens, a pair of guide portions extending in a radial direction of the optical disc and disposed on both sides of the bobbin, and a shaft slidable by the guide portions. A pair of slide portions supported and disposed on both sides of the bobbin, a suspension spring formed in a plate shape and elastically supporting the bobbin, an actuator magnet disposed substantially parallel to the guide portion, and the actuator magnet A focus coil and a tracking coil held on the bobbin so as to face the
The focus coil and the tracking coil are arranged so that surfaces of the focus coil and the tracking coil facing the actuator magnet form substantially the same surface, the suspension spring is formed in a rectangular ring shape, and the plate is formed. Shape of the optical disk
If substantially parallel arrangement, wherein the suspension bar in front Symbol bobbin the slide portion and the fixed end of the Suspension <br/> Nbane
A movable end of the suspension spring, and furthermore, two substantially rectangular annular sides of the suspension spring are inserted into the optical disk .
Disposed on the peripheral side and the outer peripheral side, which is constituted in a doubly supported beam structure co in the circumferential direction and the radial direction of the optical disc.

[0006]

In this construction, since the optical system is integrated with the bobbin, the position of the optical system does not fluctuate during the movement of the bobbin. Improvement and simplification of assembly are possible. Furthermore, the suspension spring has a substantially rectangular ring shape.
Fix the bobbin in the center of each formed
Fix each of the pair of slides to both sides of the
And the ends of the optical disc in the circumferential and radial directions are
, Suspension supported at both ends by sliding parts
The bobbin is held by a spring to provide a doubly supported structure.
Therefore, position fluctuation of the optical system during bobbin movement is suppressed and light
The scientific position can be accurately maintained. Further, a focus coil and a tracking coil are provided on the bobbin holding the objective lens, and the conventional tracking drive and feed drive are used only by energizing the tracking coil, and a magnetic circuit that performs focusing drive, tracking drive, and feed drive is simply provided. By making the opposing sides of the focus coil and the tracking coil opposite to the actuator magnet on the same plane, the gap of the magnetic circuit can be narrowed, so that the efficiency and size of the actuator can be increased, and high reliability and low cost can be achieved. An optical disk device can be realized.

[0007]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a plan view of an optical disk device according to one embodiment of the present invention, FIG. 2 is a perspective view of the optical disk device according to one embodiment of the present invention, and FIG. 3 is an exploded perspective view of the optical disk device according to one embodiment of the present invention. , FIG. 4, FIG. 5, FIG. 6, and FIG. 7 are respectively a line EE, a line FF, and a line G-G of the optical disk device according to the embodiment of the present invention shown in FIG.
It is G, line HH sectional drawing. 1, 2 and 3, a bobbin 21 emits a laser beam as shown in FIG.
The laser unit 20 to detect the laser light and the optical disk 1
An objective lens 22 for condensing the light, a pair of reflection mirrors 23 for guiding the laser light emitted from the laser unit 20 to the objective lens 22
Is provided. Even if this reflection mirror 23 is only one,
Laser unit 20 and objective lens without reflection mirror 23
22 layouts are possible. Numeral 24 denotes a carriage base on which two guide shafts 25 are attached along the radial direction of the optical disc 1. Reference numeral 26 denotes an actuator magnet for moving the bobbin 21, which is attached to the carriage base 24 in parallel with the guide shaft 25. Reference numeral 27 denotes a back yoke made of a ferromagnetic material, which is fixed in contact with the actuator magnet 26. In this embodiment, the guide shaft 25 is made of a ferromagnetic material, so that the guide shaft 25 and the actuator magnet
26 and the back yoke 27 constitute a magnetic circuit. 28
Is a focus coil for moving the bobbin 21 in the focus direction (the direction of arrow C (FIG. 2)), and is fixed to the bobbin 21 so as to face the actuator magnet 26 as shown in FIG. Reference numeral 29 denotes a tracking coil for moving the bobbin 21 in the tracking direction (the direction of arrow D (FIG. 1)).
It is fixed to the bobbin 21 so as to face the actuator magnet 26 so that the guide shaft 25 passes through 29 itself.
Reference numerals 30 and 31 denote a spindle slider and a guide slider supported by the guide shaft 25, respectively. The spindle slider 30 is slidable along the guide shaft 25 as shown in FIG. In addition to being slidable along the surface of the optical disc 1, it can be moved in a direction perpendicular to the axis of the guide shaft 25. 32 is a suspension spring, as shown in FIG. 3, to form a plate-like elastic body into a rectangular annular places the two sides in the inner periphery side and the outer periphery side of the optical disk. Then, the bobbin 21 is fixed to the central portion of the two sides of the suspension spring 32,
Securing the opposite ends of the two sides of the suspension spring 32 positioned on both sides of the bobbin 21 to the main shaft the slider 30 and the guide slider 31. In this manner, both ends of the optical disc in the circumferential direction and the radial direction are bobbins 21 at both ends by the suspension spring 32 supported by the main spindle slider 30 and the guide slider 31.
Can be configured into a doubly supported structure, bobbin
21 is the focus direction by this suspension spring 32
(In the direction of arrow C (FIG. 2)).
Reference numeral 33 denotes a signal flexure for transmitting an electric signal between a control board for controlling the entire apparatus and the laser unit 20, which is connected to the laser unit 20 and fixed to the carriage base 24. Reference numeral 34 denotes an actuator flexure for transmitting electric signals between the control board and the focus coil 28 and the tracking coil 29. The actuator flexure 34 is connected to the focus coil 28 and the tracking coil 29 and fixed to the carriage base 24. As shown in FIG. 7, a spindle motor for rotating the optical disc 1 is provided with a bearing 35 provided on the carriage base 24, a spindle coil 36 disposed around the bearing 35, and a bearing 35 rotatable. Spindle shaft 37 supported on the disk, and a turntable fixed to the spindle shaft 37 for holding the optical disc 1
And a spindle magnet 39 provided on the turntable so as to face the spindle coil.

The operation of the optical disk apparatus configured as described above will be described below. As shown in FIG.
Laser light emitted from a semiconductor laser provided in the laser unit 20 is reflected by a pair of reflection mirrors 23 and guided to the objective lens 22. The diameter of the laser light is narrowed by the objective lens 22 so that the data on the optical disk 1 can be read. The reflected light from the optical disk 1 is reflected by the reflection mirror 23 via the objective lens 22, guided to a photodetector provided in the laser unit 20, and output as an electric signal.

Next, a focusing operation for detecting data recorded on the optical disc 1 will be described. The focus coil 28 is located in a magnetic circuit composed of an actuator magnet 26, a back yoke 27, and a guide shaft 25, as shown in FIG. At the same time, the bobbin 21 and the objective lens 22 are driven in the focus direction (the direction of arrow C). At this time, the bobbin 21 holding the objective lens 22 is fixed to the center of two sides of the suspension spring 32 by a pair of upper and lower suspension springs 32.
And the suspension spring 32 is supported by the main spindle slider 30 and the guide slider 31 at positions on both sides of the bobbin 21. Therefore, the main spindle slider 30 rotates about the guide shaft 25, and the guide slider 31 While rotating about the shaft 25, the suspension spring 32 is elastically deformed by moving in the direction perpendicular to the axis of the guide shaft 25, and the bobbin 21 moves in the focus direction (the direction of arrow C). this
In the process of movement, the position fluctuation of the optical system given to the bobbin 21 is suppressed.
The optical position can be precisely maintained. Also,
In this embodiment, the suspension spring 32 is a spring that connects the bobbin 21 and the spindle slider 30, and the suspension spring 32 is a bobbin 21 and a guide slider.
Although the upper and lower springs are integrally configured with a spring connecting the spring 31 and the spring, the respective springs may be further divided.

Next, the tracking operation will be described. The tracking coil 29 held by the bobbin 21 is located in a magnetic circuit composed of the actuator magnet 26, the back yoke 27, and the guide shaft 25, similarly to the focus coil 28, and energizes the tracking coil 29. And the bobbin 21 and the objective lens 22 move in the tracking direction together with the tracking coil 29 by electromagnetic action.
(In the direction of arrow D). Since the positions of the opposing sides of the focus coil 28 and the tracking coil 29 facing the actuator magnet 26 are provided on the bobbin 21 so that the magnetic flux gap between the actuator magnet 26 and the guide shaft 25 can be narrowed, The magnetic flux density acting on the coil 29 increases, and the actuator effect can be improved. The objective lens 22 can be moved over the entire recording area in the radial direction of the optical disc 1 by this tracking operation, and the spindle slider 30 and the main shaft slider 30 that move in the radial direction of the optical disc 1 together with the bobbin 21 holding the objective lens 22. By providing the guide slider 31 slidably on the pair of guide shafts 25 and connecting the bobbin 21 with the suspension spring 32, the main spindle slider 30 and the guide slider 31 that move together with the objective lens 22 can be reduced in size and weight. Since the bobbin 21 can be driven at a high speed together with the main spindle slider 30 and the guide slider 31 with the reduction in weight, it is possible to discharge the feed portion which was conventionally required.

With regard to the spindle drive, by energizing the spindle coil 36 shown in FIG. 7, the turntable 38 rotates together with the optical disc 1 by the electromagnetic action with the spindle magnet 39. The data recorded on the optical disc 1 is reproduced by the above-described focusing drive, tracking drive, and spindle drive.

As described above, in this embodiment, the laser unit 20 for emitting and detecting the laser beam and the objective lens 22 for condensing the laser beam from the laser unit 20 on the optical disc 1 are provided.
Are integrated with the bobbin 21, the bobbin 21 in the configuration in which only the objective lens 22 is provided on the bobbin 21.
The relative position between the objective lens 22 and the laser unit 20 caused by the movement of the laser unit 20 does not occur, so that the precision of components such as the guide member of the bobbin 21 and the position adjustment problem are reduced, and the optical performance is improved. Improvement and simplification of assembly are possible .
Also, the focus coil 28 and tracking coil 29 provided in the bobbin 21 that holds the objective lens 22, also serves as a tracking drive and the feed drive in the tracking coils 29, and the focusing drive, a magnetic circuit for performing a tracking drive and feed drive Are shared by the actuator magnet 26, the back yoke 27, and the guide shaft 25, and the opposite sides of the focus coil 28 and the tracking coil 29 facing the actuator magnet 26 are flush with each other. Since the interval of 25 can be narrowed, the size and efficiency of the actuator can be reduced. In addition, bobbins
21 the ends of the circumferential direction and the radial direction of the optical disc together, since it is configured in a doubly supported beam structure holding the suspension spring 32 which is supported by the main shaft slider 30 and guide the slider 31 at both ends, the optical system in the bobbin movement And the optical position can be accurately maintained. Thus, a highly reliable and inexpensive optical disk device can be provided.

In this embodiment, the focus coil 28
And tracking coil 29 are actuator magnets
The focus coil 28 and the tracking coil 29 are located in a magnetic circuit composed of the back coil 26, the back yoke 27, and the guide shaft 25. The focus coil 28 and the tracking coil 29 are shown in FIGS. As shown, it is only necessary that the sides of the focus coil 28a and the tracking coil 29a facing the actuator magnet 26a be located on the same plane in a circuit affected by the magnetism of the actuator magnet 26a. Further, in the present embodiment, a pair of guide shafts 25 are provided so as to penetrate the tracking coil 29, and the actuator magnet 26 and the back yoke 27 are provided outside the pair of guide shafts 25. The guide shaft 25, the actuator magnet 26, and the back yoke 27 of FIG.
Fig. 9 shows the guide shaft 25a and actuator magnet 2
As shown as 6a and the back yoke 27a, the actuator magnet 26a and the back yoke 27a may be arranged inside the pair of guide shafts 25a.

[0014]

As described above, according to the present invention, since the optical system such as the laser beam emission / detection means and the objective lens for condensing the laser beam on the optical disk is integrally formed on the bobbin, the conventional objective system is used. In the configuration in which only the lens is provided on the bobbin, the relative position of the optical system, which has been caused by the movement of the bobbin, does not fluctuate, and the accuracy of components such as the bobbin guide member and the position adjustment problem are reduced. Optical performance can be improved and assembly can be simplified. Also, a focus coil and a tracking coil are provided on the bobbin holding the objective lens, the tracking drive and the feed drive are shared by the tracking coil, and the magnetic circuit for performing the focusing drive, the tracking drive and the feed drive is all a single magnetic circuit. Since the opposing sides of the focus coil and the tracking coil facing the actuator magnet are made the same, the magnetic circuit by the actuator magnet can be made more efficient,
Actuators can be made smaller and more efficient. Further, the end portion of the circumferential direction and the radial direction of the optical disk are both bobbins, since it is configured in a doubly supported beam structure holding the supported suspension spring by the slider section at both ends,
Variations in the position of the optical system during bobbin movement can be suppressed and the optical position can be accurately maintained. Thus, there is an effect that a highly reliable and inexpensive optical disk device can be realized.

[Brief description of the drawings]

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

FIG. 2 is a perspective view of an optical disk device according to one embodiment of the present invention.

FIG. 3 is an exploded perspective view of the optical disc device in one embodiment of the present invention.

FIG. 4 is a sectional view taken along line EE of the optical disc device according to the embodiment of the present invention shown in FIG. 1;

FIG. 5 is a cross-sectional view taken along line FF of the optical disc device according to the embodiment of the present invention shown in FIG. 1;

FIG. 6 is a sectional view taken along line GG of the optical disc device according to the embodiment of the present invention shown in FIG. 1;

FIG. 7 is a sectional view taken along line HH of the optical disc device according to the embodiment of the present invention shown in FIG. 1;

FIG. 8 is a plan view of an optical disc device according to another embodiment of the present invention.

FIG. 9 is a sectional view taken along line II of the optical disc device in the embodiment of another example of the present invention shown in FIG.

FIG. 10 is an external view of a main part of a conventional optical disk device.

FIG. 11 is an external view of a pickup head of a conventional optical disk device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Optical disk board, 2 ... Spindle motor, 3 ... Fixed optical part, 4 ... Moving optical part, 6, 22 ... Objective lens,
7, 21 ... bobbin, 8, 28 ... focus coil,
9, 29: tracking coil, 10, 32: suspension spring, 11: head base, 12: magnet, 1
3, 24: carriage base, 14: guide roller, 1
5, 25 ... guide shaft, 16 ... feed magnet,
17… back yoke, 18… opposite yoke, 19… feed coil, 20… laser unit, 23… reflection mirror,
26… actuator magnet, 30… spindle slider, 31… guide slider, 36… spindle coil,
38 ... turntable, 39 ... spindle magnet.

──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Takashi Haruguchi 1006 Kazuma Kadoma, Kazuma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (56) References JP-A-5-334690 (JP, A) Japanese Utility Model 4 -137515 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G11B 7/085 G11B 7/09 G11B 7/095

Claims (2)

(57) [Claims] 1. An optical disk device for mounting and rotating an optical disk, irradiating the optical disk with a laser beam, and reproducing or recording information recorded on the optical disk from the reflected light, wherein the laser beam is emitted. A laser unit for detecting the reflected light, an objective lens for condensing the laser light on the optical disk, a bobbin for holding the laser unit and the objective lens, and both sides of the bobbin extending in the radial direction of the optical disk. A pair of guide portions, a pair of slide portions pivotally supported by the guide portions and disposed on both sides of the bobbin, and a suspension spring formed in a plate shape and elastically supporting the bobbin. An actuator magnet disposed substantially parallel to the guide portion; and an actuator magnet facing the actuator magnet. A focus coil and a tracking coil held by the bobbin, and the focus coil and the tracking coil such that surfaces of the focus coil and the tracking coil facing the actuator magnet form substantially the same surface. And the suspension spring is formed in a rectangular ring shape , and the plate-shaped surface is
If substantially parallel arrangement, the optical disk apparatus, characterized in that the bobbin the slide portion and a fixed end of the Suspension <br/> Nbane configured to doubly supported beam structure to the movable end of the suspension spring. 2. A rectangular annular 2 of said suspension spring.
Sides was placed on the inner peripheral side and outer peripheral side optical disk, the two sides
Fixing the two ends to the slide portion front central portion of the two sides
Fixed to serial bobbin, before SL optical disc in the circumferential direction and the radial direction and the optical disk apparatus according to claim 1, characterized by being configured to doubly supported beam structure in a co-in.