JPH06333252A - Optical pickup - Google Patents

Abstract

PURPOSE:To simplify the assembling and to miniaturize a magnetic circuit by superposing no focusing force generation side on a tracking force generation side of a focus coil and a track coil with a bobbin shape. CONSTITUTION:The one ends of four of supporting members 22 with elasticity are stuck to a fixed part 21. The magnetic flux B nearly parallel to a recording surface D of an optical recording medium is generated by a magnet 26 and the magnetic circuits 23, 24. A beam out-goes from an objective lens 28 to the recording surface D. When a current flows through the focus coil 29 by a control circuit, since the focusing force generation side is intersected orthogonally with the magnetic flux B, the thrust approaching/separating to/from the optical recording medium is generated, and the focusing of an optical pickup is performed. On the other hand, when the current flows through the track coil 30 by the control circuit, since the tracking force generation sides 30a, 30b are intersected orthogonally with the magnetic flux B, the thrust in the direction of traversing a track on the recording surface D is generated, and the tracking of the optical pickup is performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a support member having elasticity, one end of which is fixed to a base side, a magnetic circuit for generating a magnetic flux substantially parallel to a recording surface of an optical recording medium, and the above optical recording. It has an objective lens that emits a beam to the recording surface of the medium,
A bobbin, to which the other end of the support member is fixed, is wound substantially parallel to the recording surface of the optical recording medium, is provided on the bobbin, is orthogonal to the magnetic flux of the magnetic circuit, and approaches the optical recording medium. / A focus coil having a focus force generation side that generates thrust to be separated from each other, wound in a direction substantially perpendicular to the recording surface of the magneto-optical recording medium, provided on the bobbin, and orthogonal to the magnetic flux of the magnetic circuit, An optical pickup comprising: a track coil having a track force generating side that generates a thrust force in a direction traversing a track of the optical recording medium.

[0002]

2. Description of the Related Art First, a first conventional example will be described with reference to FIGS. 6 is a perspective view of the optical pickup of the first conventional example, FIG. 7 is a side view of FIG. 6, and FIG. 8 is a plan view of FIG.

In these drawings, reference numeral 1 is a fixed portion provided on the apparatus side. One end portion of four elastic supporting members 2 is fixed to the fixing portion 1. Magnetic circuits 3 and 4 generate a magnetic flux B substantially parallel to the recording surface D of the optical recording medium (see FIG. 7). These magnetic circuits 3 and 4 have a substantially U-shaped yoke 5 having an outer yoke 5a and an inner yoke 5b.
And a magnet 6 provided on the inner wall surface of the outer yoke 5a of the yoke 5.

A bobbin 7 has an objective lens 8 for emitting a beam to a recording surface D of the optical recording medium, and the other end of the supporting member 2 is fixed to the bobbin. 9 is the recording surface D of the optical recording medium
A focus coil which is wound substantially in parallel with, is provided on the bobbin 7, is orthogonal to the magnetic flux B of the magnetic circuits 3 and 4, and has the focus force generating sides 9a and 9b that generate thrust force that moves toward and away from the optical recording medium. is there.

Numeral 10 is wound in a direction substantially perpendicular to the recording surface D of the magneto-optical recording medium, two focusing force generating sides 9a and 9b (bobbin 7) of the focusing coil 9 are provided, and a magnetic flux B of the magnetic circuit is formed. A track force generating side 10 that generates a thrust force in a direction orthogonal to the track of the optical recording medium.
It is a track coil having a and 10b.

Next, the operation of the above configuration will be described. When a control circuit (not shown) supplies a current to the focus coil 9, the focus force generating sides 9a and 9b cause the magnetic flux B of the magnetic circuits 3 and 4 to flow.
Since they are orthogonal to the focus force generation side 9a,
At 9b, a thrust (F) that moves toward and away from the optical recording medium is generated, and focusing of the optical pickup is performed.

When a control circuit (not shown) applies a current to the track coil coil 10, the track force generating side 10a,
Since 10b is orthogonal to the magnetic flux B of the magnetic circuits 3 and 4,
On these track force generating sides 10a and 10b, a thrust force (T) in a direction crossing the track of the recording surface D of the optical recording medium is generated, and tracking of the optical pickup is performed.

Next, a second conventional example will be described with reference to FIGS. 9 to 11. 9 is a perspective view of a second conventional optical pickup, FIG. 10 is a side view of FIG. 9, and FIG. 11 is a plan view of FIG.

In these figures, reference numeral 11 is a fixing portion provided on the apparatus side. One end of each of four elastic supporting members 12 is fixed to the fixing portion 11. 1
Magnetic circuits 3 and 14 generate a magnetic flux B substantially parallel to the recording surface D (see FIG. 10) of the optical recording medium. These magnetic circuits 13 and 14 are composed of a substantially U-shaped yoke 15 having an outer yoke 15a and an inner yoke 15b, and a magnet 16 provided on the inner wall surface of the outer yoke 15a of the yoke 15.

Reference numeral 17 is a bobbin having an objective lens 18 for emitting a beam to the recording surface D of the optical recording medium, and the other end of the supporting member 12 being fixed. Reference numeral 19 is a winding force which is wound substantially parallel to the recording surface D of the optical recording medium, is provided on the bobbin 17, is orthogonal to the magnetic flux B of the magnetic circuits 13 and 14, and generates a thrust force that moves toward and away from the optical recording medium. Side 1
It is a focus coil having 9a and 19b.

The reference numeral 20 is wound in a direction substantially perpendicular to the recording surface D of the magneto-optical recording medium, and the focus force generating sides 9a and 9b (bobbin 7) of the focus coil 19 are wound in a direction 2
The track coil is provided with two track force generating sides 20a and 20b which are orthogonal to the magnetic flux B of the magnetic circuit and generate thrust in the direction transverse to the track of the optical recording medium.

Next, the operation of the above configuration will be described. When a control circuit (not shown) supplies a current to the focus coil 19,
The focus force generating sides 19a and 19b are magnetic circuits 13 and 14, respectively.
Since the magnetic flux B is orthogonal to the magnetic flux B, a thrust force (F) for approaching / separating from the optical recording medium is generated on the focus force generating sides 19a, 19b, and focusing of the optical pickup is performed.

When a control circuit (not shown) supplies a current to the track coil coil 20, the track force generating side 20a,
Since 20b is orthogonal to the magnetic flux B of the magnetic circuits 13 and 14, the track force generating sides 20a and 20b generate a thrust force (T) across the track of the recording surface D of the optical recording medium, and the optical pickup Is tracked.

[0014]

However, FIG. 6 to FIG.
In the first conventional optical pickup shown in (1), the thin square track coil 10 must be accurately overlapped and adhered to the focus coil 9, and the workability of assembly is poor.

In the second conventional optical pickup shown in FIGS. 9 to 11, the number of track coils 20 is two, and the first conventional optical pickup requires four track coils 10. Although the number is smaller than that of the conventional one, the workability is poor because the track coil 20 must be attached after the focus coil 19 is attached to the bobbin 17.

Furthermore, in the first and second conventional optical pickups, since the track coil overlaps the focus generation side, the magnetic gap of the magnetic circuit becomes large, and the magnetic circuit must be made large to obtain a predetermined magnetic flux. It is necessary to exclude the miniaturization and cost reduction of the device.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an optical pickup which is easy to assemble and is capable of miniaturizing a magnetic circuit.

[0018]

According to a first aspect of the present invention for solving the above-mentioned problems, a supporting member having elasticity and having one end fixed to a base side is substantially parallel to a recording surface of an optical recording medium. A bobbin having a magnetic circuit that generates a magnetic flux, an objective lens that emits a beam toward the recording surface of the optical recording medium, and the other end of the supporting member is fixed, and a recording surface of the optical recording medium. A focus coil that is wound substantially in parallel, is provided on the bobbin, is orthogonal to the magnetic flux of the magnetic circuit, and has a focus force generation side that generates a thrust force that moves toward and away from the optical recording medium; and the magneto-optical recording medium. Track coil, which is wound in a direction substantially perpendicular to the recording surface of the optical disk, is provided on the bobbin, is orthogonal to the magnetic flux of the magnetic circuit, and has a track force generating side for generating a thrust in a direction crossing the track of the optical recording medium. Light with In the pickup, the focus force generating side of the focus coil and the track force generating side of the track coil are arranged so as not to overlap with each other.

According to a second aspect of the invention, the focus coil and the track coil of the first aspect of the invention are bobbin windings.

[0020]

According to the optical pickup of the first aspect of the present invention, the focus force generating side of the focus coil disposed in the magnetic gap of the magnetic circuit and the track force generating side of the track coil are prevented from overlapping each other. The magnetic gap can be reduced, and the magnetic circuit can be downsized.

In the optical pickup of the second aspect of the invention, the focus coil and the track coil are bobbin wound, so that the assembly is simplified.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described with reference to the drawings. 1 is a perspective view of an optical pickup according to an embodiment of the present invention, FIG. 2 is a side view of FIG. 1, FIG. 3 is a plan view of FIG. 1, and FIG. 4 is a view for explaining a bobbin in FIG.
Is a plan view and (b) is a front view.

In these figures, reference numeral 21 is a fixing portion provided on the apparatus side. One end of each of four elastic support members 22 is fixed to the fixed portion 21. Two
Magnetic circuits 3 and 24 generate a magnetic flux B substantially parallel to the recording surface D (see FIG. 2) of the optical recording medium. These magnetic circuits 23, 24 are composed of a substantially U-shaped yoke 25 having an outer yoke 25a and an inner yoke 25b, and a magnet 26 provided on the inner wall surface of the outer yoke 25a of the yoke 25.

Reference numeral 27 is a bobbin having an objective lens 28 for emitting a beam to the recording surface D of the optical recording medium, and the other end of the supporting member 12 being fixed. As shown in FIG. 4, track coil holding portions 27a extending in the front-rear direction are formed on the upper and lower surfaces of both sides of the bobbin 27,
Further, inside the track coil holding portions 27a, focus coil holding grooves 27b are formed.

29 is wound substantially parallel to the recording surface D of the optical recording medium, and has a focus coil holding groove 27b of the bobbin 27.
Are focus coils which are provided in the respective magnetic circuits 23 and 24 and which are orthogonal to the magnetic flux B of the magnetic circuits 23 and 24, and have the focus force generating sides 29a and 29b which generate thrust forces that move toward and away from the optical recording medium.

Numerals 30 are wound in a direction substantially perpendicular to the recording surface D of the magneto-optical recording medium, respectively provided in the track coil holding portions 27a of the bobbin 27, orthogonal to the magnetic flux B of the magnetic circuit, and track of the optical recording medium. It is a track coil having track force generation sides 30a and 30b that generate thrust in a direction traversing.

Next, the operation of the above configuration will be described. When a control circuit (not shown) supplies a current to the focus coil 29,
Focusing force generating sides 29a and 29b are magnetic circuits 23 and 24.
Since the magnetic flux B is orthogonal to the magnetic flux B, a thrust force (F) for approaching / separating from the optical recording medium is generated on the focus force generating sides 29a, 29b, and focusing of the optical pickup is performed.

When a control circuit (not shown) supplies a current to the track coil coil 30, the track force generating side 30a,
Since 30b is orthogonal to the magnetic flux B of the magnetic circuits 13 and 14, a direction thrust (T) across the tracks on the recording surface D of the optical recording medium is generated on these track force generating sides 30a and 30b, and the optical pickup Is tracked.

According to the above construction, the bobbin-shaped focus coil 29 and the track coil 30 can be directly attached to the focus coil holding groove 27b and the track coil 27a of the bobbin 27. Therefore, the assembling workability is good.

Further, since there is no portion where the focus force generating sides 29a and 29b of the focus coil 29 and the track force generating sides 30a and 30b of the track coil 30 overlap, the magnetic gap of the magnetic circuits 23 and 24 can be narrowed.
The magnetic circuit can be downsized and its performance can be improved.

The present invention is not limited to the above embodiment. For example, as shown in FIG. 5, the sides of the focus coil 50 other than the focus force generating sides 50 a and 50 b and the track force generating sides 51 a and 5 a of the track coil 51.
It does not matter if it is configured so as to overlap the sides other than 1b.

[0032]

As described above, according to the present invention, the focus force generating side and the track force generating side of the bobbin-shaped focus coil and the track coil are prevented from overlapping with each other, so that the assembly is easy and the magnetic circuit is easy. It is possible to realize an optical pickup that can be miniaturized.

[Brief description of drawings]

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

FIG. 2 is a side view of FIG.

FIG. 3 is a plan view of FIG.

4 (a) is a plan view and FIG. 4 (b) is a front view for explaining the bobbin in FIG.

FIG. 5 is a diagram illustrating another embodiment.

FIG. 6 is a perspective view of an optical pickup of a first conventional example.

FIG. 7 is a side view of FIG.

FIG. 8 is a plan view of FIG.

FIG. 9 is a perspective view of an optical pickup of a second conventional example.

FIG. 10 is a side view of FIG.

FIG. 11 is a plan view of FIG. 9.

[Explanation of symbols]

 21 Fixed Part 22 Support Member 23, 24 Magnetic Circuit 25 Yoke 26 Magnet 27 Bobbin 28 Objective Lens 29 Focus Coil 29a, 29b Focus Force Generation Side 30 Track Coil 30a, 30b Track Force Generation Side

Claims (2)

[Claims] 1. A support member (22) having elasticity and having one end fixed to a base side, a magnetic circuit (23, 24) for generating a magnetic flux substantially parallel to a recording surface of an optical recording medium, A bobbin (27) having an objective lens (28) that emits a beam toward the recording surface of the optical recording medium, and the other end of the supporting member (22) being fixed to the recording surface of the optical recording medium. A focus force generating side (29a, 29a, which is wound substantially in parallel, is provided on the bobbin (27), is orthogonal to the magnetic flux of the magnetic circuit (23, 24), and generates a thrust force that moves toward and away from the optical recording medium. Focus coil (29) with 29b)
And the magnetic circuit (2), which is wound in a direction substantially perpendicular to the recording surface of the magneto-optical recording medium and is provided on the bobbin (27).
3, 24) which is perpendicular to the magnetic flux of (3, 24) and generates a thrust force in a direction crossing the tracks of the optical recording medium.
an optical pickup comprising a track coil (30) having a, 30b), wherein a focus force generating side (29a, 29b) of the focus coil (29) and a track force generating side (30a) of the track coil (30). , 30b) so as not to overlap with each other. 2. The optical pickup according to claim 1, wherein the focus coil (29) and the track coil (30) are bobbin windings.