JP2576325Y2 - Optical pickup for optical disk drive - Google Patents

Description

[Detailed description of the invention]

[0001]

The present invention relates to an optical disk device.
In particular, the present invention relates to an optical pickup for projecting light onto an optical disc or receiving reflected light from the optical disc.

[0002]

2. Description of the Related Art An optical disk device is configured to write information by projecting a laser beam emitted from a laser light source onto an optical disk, or to read information by detecting the reflected light. An optical pickup is provided for projecting or receiving light. Conventionally, this type of optical pickup has a configuration in which a guide rail is extended in a radial direction of an optical disk and light is projected and received on the optical disk by reciprocating an optical system on the guide rail. I have. On the other hand, in recent years, a swing arm type optical pickup has been proposed. This swing arm type optical pickup
The swing arm is configured to be able to swing around a base end, and the tip is moved in a substantially radial direction of the optical disk with the swing. Then, a laser light source and an optical system are integrally formed with the swing arm, so that light is projected onto the optical disk and reflected light is detected.

[0003]

In the optical pickup having this structure, since the laser light source and the optical system are integrally mounted on the swing arm, the weight of the swing arm increases, and the swing arm swings. The driving source of the optical pickup becomes large, which becomes an obstacle to miniaturization of the optical pickup. Further, since the weight of the swing arm is large, its inertia is also increased, and there is a problem that an increase in access speed to a desired track of the optical disc is hindered. SUMMARY OF THE INVENTION An object of the present invention is to provide an optical pickup capable of miniaturizing and enabling high-speed access to an optical disk.

[0004]

SUMMARY OF THE INVENTION The present invention is directed to a swing arm type optical disc apparatus, wherein an optical system is mounted on a fixed optical system including a laser light source and an optical system for shaping laser light, and on the swing arm. is said that the light from the fixed optical system provided at the distal end portion of the reflecting mirror and the swing arm is reflected is reflected by the reflection mirror light
The projection on the optical disc is separated composed of a movable optical system including an objective lens, the reflection mirror is the swing
The swing arm swings at the swing center position of the arm.
Is configured to be rotatable on a plane parallel to the moving plane, and
The reflecting mirror is moved by the swinging rotational force of the swing arm.
Rotary drive with half the swing angle of the swing arm
A configuration is provided in which a rotation drive mechanism for moving is provided . For example, the swing arm is rotatably supported around the fixed cylinder which is fixed to the device, the center position of the stationary cylinder the first of the first rotating member is rotatably supported
The reflecting mirror to the rotating body is supported, a main gear provided on the swing arm and coaxial, and従歯pulley provided coaxially with the first rotating body, first to be meshed with the main gear
The rotation driving mechanism in a second intermediate gear with integrated intermediate gear coaxially configured to be meshed with the intermediate gear and the従歯wheel, rotation ratio between the main gear and the first intermediate gear, said従歯wheel The rotation ratio is set to 1/2 of the rotation ratio with the second intermediate gear. Also configured second rotating member as the rotary sleeve rotatable around a fixed shaft which is fixed to the device, and the said reflecting mirror is supported on a second rotary member, said Sui <br/> Nguamu is is rotatably supported around said second rotary member, and internal gear provided coaxially with the swing arm, before
Serial and fixed wheel having a second rotating body to the fixed shaft for rotatably supporting and simultaneously mesh with these internal gear and the fixed gear, and before
Before being composed of a planetary gear rotatably supported by the second rotating body
The rotation drive mechanism is provided.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings. FIG. 1 is a plan view of a first embodiment of the present invention, and FIG.
FIG. 2 is a cross-sectional view of the line, in which 1 is an optical disk, which is driven to rotate by a rotation mechanism 2. Reference numeral 3 denotes a swing arm supported so as to be able to swing in a horizontal plane with respect to the recording surface of the optical disc 1, and is supported by a rotary bearing 6 provided on the outer peripheral side of a cylindrical fixed cylinder 5 erected on a base 4 of the apparatus. Is done. A coil 8 is attached to a base end of the swing arm 3 by a yoke 7, and the coil 8 and an arc-shaped magnet 9 arranged so as to sandwich the coil 8 vertically constitute a linear motor. Thus, the swing arm 3 is configured so that the tip end portion thereof is reciprocated between the outer circumference and the inner circumference position of the optical disc 1.

A rotary shaft 11 is supported at the center of rotation of the swing arm 3 by a rotary bearing 10 provided on the inner peripheral side of the fixed cylinder 5. A mirror 12 is supported. Furthermore,
A laser light source 13 and an optical system 14 are disposed at one side of the swing arm 3, and the optical axis thereof is opposed to the first reflection mirror 12. A second reflecting mirror 15 and an objective lens 16 are held at the tip of the swing arm 3. Note that the first reflection mirror 12 is an optical system 14.
The second reflecting mirror 15 is provided so as to reflect light in the horizontal direction between the first reflecting mirror 12 and the objective lens 16. is set up. In this case, a fixed optical system is constituted by the laser light source 13 and the optical system 14 provided on the fixed part of the apparatus, and the first reflecting mirror 12, the second reflecting mirror 15 and the objective lens 16 mounted on the swing arm 3. Thus, a movable optical system that is moved with the swing of the swing arm 3 is configured.

Further, a part of the swing arm 3 includes:
As shown in a schematic perspective view in FIG. 2, an arc-shaped main gear 17 concentric with the rotating shaft 11 is integrally formed, and a sector-shaped slave gear 18 concentric with the rotating shaft 11 is integrally formed with the rotating shaft 11. Has been attached. The first intermediate gear 19 and the second intermediate gear 2 meshed with the main gear 17 and the slave gear 18, respectively.
0 is integrally formed as an intermediate gear 21, and the integrated intermediate gear 21 is rotatably supported by a fixed shaft 22 erected on the base 4. Here, the pitch circle radius of the main gear 17 is r1, the pitch circle radius of the slave gear 18 is r2,
The pitch circle radius of the intermediate gear 19 is r3, and the second intermediate gear 20
When the pitch circle radius of r is r4, they are set to have a relationship of 2 (r1 / r3) = r2 / r4. That is, the main gear 17
And the first intermediate gear 19 are set to have a rotation ratio of 1/2 of the rotation ratio of the slave gear 18 and the second intermediate gear 20.

Therefore, according to the optical pickup of this construction, when the coil 8 is energized, the linear motor constituted by the magnet 9 is driven, and the swing arm 3 swings around the fixed cylinder 5 by the rotary bearing 6. Is moved along the radial direction of the optical disc 1,
The objective lens 16 is moved between the inner circumference and the outer circumference of the optical disc 1. The light from the laser light source 13 passes through the optical system 14, is reflected by the first reflection mirror 12, is further reflected by the second reflection mirror 15, and is imaged on the recording surface of the optical disc 1 by the objective lens 16. The reflected light from the optical disc 1 is transmitted to the objective lens 16, the second reflecting mirror 15, the first
The light is reflected by the optical path of the reflection mirror 12 to the optical system 14 and received by a light receiving unit (not shown).

When the swing arm 3 is swung, the main gear 17 integral with the swing arm 3 is rotated around the central axis, and this rotation is caused by the rotation of the first intermediate gear 19 and the second intermediate gear 2.
0 is transmitted to the intermediate gear 21 and further from the driven gear 18
To the rotating shaft 11 integrated with the driven gear 18 to rotate the rotating shaft 11. Here, since the pitch circle radii of the respective gears are set as in the above formula, the slave gear 18 is rotated at a half rotation angle of the main gear 17, so that the swing arm 3 can be freely rotated. The first reflection mirror 12 mounted on the rotating shaft 11 is always rotated by the angle θ / 2. As a result, from the law of light reflection, the optical system 14
Is reflected by the first reflecting mirror 12, the reflected light is always reflected toward the second reflecting mirror 15 at the tip of the swing arm 3, and conversely from the second reflecting mirror 15. Is reflected by the first reflecting mirror 12,
The reflected light is always reflected toward the optical system 14.

Therefore, by separating the optical system of the optical pickup into a fixed optical system and a movable optical system and mounting only the movable optical system on the swing arm 3, the weight of the swing arm 3 is reduced by the amount of the fixed optical system. Can be done. Thus, the drive source for swinging the swing arm 3 can be reduced in size, and the optical pickup can be reduced in size. Further, by reducing the weight of the swing arm 3, high-speed access to the optical disc 1 is realized.

FIG. 3 is a plan view of a second embodiment of the present invention and a sectional view taken along line BB of FIG. The same parts as those in the first embodiment are denoted by the same reference numerals. In this embodiment, a fixed shaft 23 is erected on the base 4 at the rotation center position of the swing arm 3, and a rotating sleeve 25 is rotatably supported on the fixed shaft 23 by a rotating bearing 24. The swing arm 3 is swingably supported by a rotary bearing 26 on the outer peripheral surface of the swing arm 3. This rotating sleeve 25
A first reflection mirror 12 is mounted on the upper surface of the first mirror. The swing arm 3 is mounted with a second reflecting mirror 15 and an objective lens 16 and is swung by a linear motor composed of a coil 8 and a magnet 9. It goes without saying that the optical system 14 is provided.

As shown in a schematic perspective view of FIG. 4, the fixed shaft 23 has a fixed gear 2 concentric with the center of rotation.
The swing arm 3 is integrally formed with an arcuate internal gear 28 concentric with the center of rotation. A planetary gear 29 simultaneously meshed with the fixed gear 27 and the internal gear 28 has a small shaft 3
It is supported so as to be free to rotate by 0.

According to the optical pickup having this configuration, the swing arm 3 is swung by the linear motor, and the light from the laser light source 13 passes through the optical system 14 and is transmitted to the first reflection mirror 12 and the second reflection mirror 15. The light is sequentially reflected and formed into an image on the recording surface of the optical disk 1 by the objective lens 16, and the reflected light from the recording surface of the optical disk 1 is directed to the optical system 14 by the second reflection mirror 15 and the first reflection mirror 12. The reflection is the same as in the first embodiment.

In this embodiment, when the swing arm 3 is swung, the internal gear 28 is rotated integrally therewith, and this rotation is transmitted to the planetary gear 29 and further transmitted to the fixed gear 27. . However, since the fixed gear 27 is not rotated, as a result, the planetary gear 29 revolves around the center of rotation, and the rotating sleeve 25 supporting the planetary gear 29 is rotated. And
The rotation angle of the rotary sleeve 25 is set to の of the swing angle of the swing arm 3 according to the principle of the planetary gear mechanism.
The rotation angle of 2 is の of the swing angle of the swing arm 3. Thus, as in the case of the first embodiment, the first reflecting mirror 12 can always reflect light between the optical system 14 and the second reflecting mirror 15.

Also in this embodiment, since the optical system is separated into a fixed optical system and a movable optical system, and only the movable optical system is mounted on the swing arm 3, the weight of the swing arm 3 can be reduced. The size of the pickup is reduced, and high-speed access is enabled. Here, swing arm 3
The mechanism for transmitting the rotation angle to the rotating bodies 11 and 25 having the first reflecting mirror 12 in a decelerated state from the other gear mechanism, the belt mechanism, and the friction gear regardless of the gear mechanism in each of the above-described embodiments. Various mechanisms such as a mechanism can be applied. In addition, when the present invention is applied to an optical disk device capable of recording information on the front and back surfaces provided in recent years, the swing arm of the present invention is provided on each of the swing arms on each surface after the swing arm is positioned opposite to both surfaces of the optical disk. The configuration may be applied. The first reflection mirror 12 is mounted via a driving device such as an actuator, and is configured to rotate by a small angle based on a track error signal obtained from a signal detection system (not shown). And so on.

[0016]

[Effect of the Invention] As described above, in the present invention, the optical system is separated into a fixed optical system and a movable optical system, and only the movable optical system is mounted on the swing arm. In addition to the downsizing of the driving source, the overall size of the optical pickup can be reduced, and high-speed access to the optical disk can be realized. In addition, the reflecting mirror is configured to be driven to rotate independently of the swing arm, and the reflecting mirror is configured to be driven to rotate at a rotation angle of に 対 し て of the swing angle of the swing arm. The optical path between the fixed optical system and the movable optical system can always be secured regardless of the swinging motion of the mirror, and the reflecting mirror uses the swinging power of the swing arm.
To rotate the reflection mirror.
There is no need to provide a separate drive source for
The structure of the device is not complicated.

[Brief description of the drawings]

FIG. 1 is a plan view of a first embodiment of the present invention and a cross-sectional view taken along line AA of FIG.

FIG. 2 is a perspective view showing a schematic configuration of a main part of FIG. 1;

FIG. 3 is a plan view of a second embodiment of the present invention and a sectional view taken along line BB of FIG.

FIG. 4 is a perspective view showing a schematic configuration of a main part of FIG. 3;

[Explanation of symbols]

 Reference Signs List 1 optical disk 3 swing arm 8 coil 9 magnet 11 rotation axis 12 first reflection mirror 13 laser light source 14 optical system 15 second reflection mirror 16 objective lens 17 main gear 18 slave gear 21 intermediate gear 25 rotating sleeve 27 fixed gear 28 internal gear 29 Planetary gear

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-1-196736 (JP, A) JP-A-3-269834 (JP, A) JP-A-3-80441 (JP, A) (58) Field (Int.Cl. ⁶ , DB name) G11B 7/135 G11B 7/085

Claims (3)

(57) [Scope of request for utility model registration] An optical disk which is driven to rotate, a swing arm which is pivotally supported at one side of the optical disk, and whose tip end swings along a radial direction of the optical disk, and records information on the optical disk , emit light for reproducing or receiving, in the optical disk apparatus comprising an optical system for light projection position is changed by the swing of the swing arm with respect to said optical disc, said optical system, a laser light source and laser light A fixed optical system including an optical system for shaping; and a fixed optical system mounted on the swing arm.
In the reflection mirror provided at the distal end portion of the reflecting mirror and the swing arm to reflect light from the fixed optical system
The reflected light is separated composed of a movable optical system including an objective lens for projecting the optical disc, the reflecting mirror
At the swing center position of the swing arm, the swing
It is configured to be rotatable on a plane parallel to the swing plane of the arm.
And the swinging rotational force of the swing arm
Rotate the reflection mirror by half the swing angle of the swing arm
A rotation drive mechanism is provided for rotationally driving at an angle.
The optical pickup of an optical disk apparatus characterized by that. Wherein said swing arm is rotatably supported around a fixed cylinder fixed to the apparatus, the rotation first of the first rotating member is rotatably supported in the center position of the fixed cylinder body the reflecting mirror is supported by a main gear provided on the <br/> swing arm coaxial with the first
Of the従歯pulley provided coaxially with the rotating body, a second that is meshed with the first intermediate gear and said従歯wheel which meshes with the main gear
The rotation driving mechanism is constituted by an intermediate gear with integrated intermediate gear coaxially, rotation ratio between the main gear and the first intermediate gear, the rotation ratio of the従歯wheel and the second intermediate gear 1/2 2. The optical pickup for an optical disk device according to claim 1 , wherein the optical pickup is set so as to satisfy the following condition. 3. is configured as a rotatable rotating sleeve around the fixed shaft that is fixed to the device a second rotating body, and the reflecting mirror supported on the second rotating member, said Sui <br / > Nguamu is rotatably supported around said second rotary member, and internal gear provided coaxially with the swing arm, before
Serial and fixed wheel having a second rotating body to the fixed shaft for rotatably supporting and simultaneously mesh with these internal gear and the fixed gear, and before
Before being composed of a planetary gear rotatably supported by the second rotating body
2. The optical pickup for an optical disk device according to claim 1 , further comprising a rotation drive mechanism.