JPH0313862Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to an optical pickup installed in a compact disc player, etc., and in particular an optical pickup in which a coil for correcting and driving an objective lens is energized via a leaf spring. This invention relates to a coil energization mechanism for a type pickup.

[Technical background and problems with conventional technology]

An optical pickup equipped in a compact disc player is provided with a correction drive device that causes a correction operation of an objective lens. This correction drive device includes a focus correction device that finely drives the objective lens toward and away from the optical disk to focus the beam spot on the recording surface of the optical disk, and a focus correction device that focuses the beam spot on the recording surface of the optical disk. There is a tracking correction device that makes the beam spot follow the information track by finely driving the beam spot in the direction along the information track.

In these correction drive devices, the member to be operated is supported by a leaf spring, and the member to be operated is generally provided with a coil, and a magnetic circuit is formed that traverses this coil. . By energizing this coil, the holding member of the objective lens and the like are slightly moved to perform correction.

In optical pickups for compact disc players, etc., miniaturization of this correction drive device is being pursued. Therefore, the wiring structure becomes complicated when connecting the lead wire to the coil provided in the operating part. Therefore, recently, a structure has been devised in which the coil is energized using a leaf spring that supports the operating member.

However, in the past, the leaf spring for focus correction drive and the leaf spring for tracking correction drive were separate bodies, so wiring was done separately for each correction leaf spring. It is inevitable that one of these two types of leaf springs will be placed inside the correction drive device. Therefore, it is easy to connect a lead wire from the outside to the leaf spring provided on the outside of the correction drive device, but it is easy to connect the lead wire from the outside to the leaf spring provided inside the correction drive device. Connecting them is an extremely difficult task.

[Purpose of this invention]

The present invention has been developed by focusing on the above-mentioned conventional problems, and in which two types of coils for correcting the objective lens are energized via leaf springs that support them, a plurality of coils are used. To provide a coil energizing mechanism for an optical pick-up, which facilitates wiring for a set of leaf springs from the outside of a correction drive device and simplifies wiring work.

[Structure of the present invention]

In the coil energizing mechanism according to the present invention, an objective lens holding member is supported on an intermediate member that is movably supported by a leaf spring, and an objective lens holding member is further supported on the intermediate member so as to be movable in a fine manner. In an optical pickup, the intermediate member is equipped with a coil for driving the intermediate member, and the objective lens holding member is equipped with a coil for driving this holding member. supported,
A coil installed in the intermediate member is electrically connected to two of the leaf springs, and the other two of the leaf springs have their tips bent,
A holding member for the objective lens is supported by this bent piece, and a coil installed in the objective lens is electrically connected to this bent piece. By forming bent pieces at the tips of the two leaf springs in this way and using these leaf springs for two types of correction operations, it is possible to access the four leaf springs supporting the intermediate member from the outside. By connecting the lead wires, it is possible to energize two types of coils.

[Example of the present invention]

Embodiments of the present invention will be described below with reference to FIGS. 1 to 3.

FIG. 1 is an exploded perspective view showing a coil energizing mechanism of an optical pickup in a compact disc player, FIG. 2 is a plan view of the optical pickup, and FIG. 3 is a side view thereof.

Reference numeral 11 shown in FIG. 2 is a turntable. This turntable 11 is driven by a motor, and an optical disk 12 installed on the turntable 11 is rotated. The optical pickup 20 faces the lower surface of the optical disc 12 and is adapted to move along the radius of the optical disc 12.

Reference numeral 21 in the figure is a slider that moves the objective lens 22 and the like along the recording surface of the optical disk 12. The objective lens 22 is provided approximately at the center of the slider 21.

The objective lens 22 is held in a lens barrel 23,
This lens barrel 23 is provided on an intermediate member 25. This intermediate member 25 has a U-shaped planar shape. That is, a pair of parallel support plates 25b extend from both sides of the central plate 25a. This support plate 25b has a triangular side surface. Two leaf springs 24 are mounted on the upper end surface of the central plate 25a of the intermediate member 25.
The other two leaf springs 26 are fixed to the lower end surface of the intermediate member 25. The base ends of the upper and lower leaf springs 24 and 26 are fixed to a support block 27.
7 is fixed on the bottom plate 21a of the slider 21. Further, a bent piece 26a is formed at a right angle at the tip of the lower leaf spring 26. The protrusion 23a on the side surface of the lens barrel 23 is connected to the bent piece 2.
It is fixed to the tip of 6a. The intermediate member 25 is supported by four upper and lower leaf springs 24 and 26 so as to be able to move slightly in the focus correction direction (Y direction), and the lens barrel 23, which is a holding member for the objective lens 22, is supported by a bent piece 26a. Therefore, it is supported for fine movement in the tracking correction direction (X direction).

Moreover, a connection protrusion 24a for a coil is integrally formed at one end of the upper leaf spring 24, and a connection protrusion 24b for a lead wire from the outside is integrally formed at the other end. Similarly, at the end of the other leaf spring 26, there is a connection protrusion 26c for a lead wire from the outside.
Furthermore, a connecting protrusion 26b for the coil is integrally formed at the tip of the bent piece 26a.

A focus coil 28 is fixed to the inner surface of the central plate member 25a of the intermediate member 25. This focus coil 28 is for finely driving the intermediate member 25 together with the objective lens 22 in the Y direction. The focus coil 28 is wound horizontally and formed into a cylindrical shape. Also focus coil 2
The ends 28a and 28b of the windings 8 are each soldered to a connecting projection 24a of the upper leaf spring 24. A pair of yokes 29a, 29b and a magnet 31 held by the yoke 29b are provided on the upper surface of the bottom plate 21a of the slider 21, and a magnetic circuit is constituted by these. These yokes 29a and 29b are connected to the bottom plate 21a by magnetic material.
is formed integrally with. As shown in Figure 3,
Yoke 29a intervenes within coil 28 so that the magnetic field created by magnet 31 crosses one side of coil 28. The upper surfaces of the yoke 29b and the magnet 31 are sloped at 45 degrees, and the reflective slope 32a of the prism 32 is bonded and fixed to this slope. This prism 32 is located directly below the objective lens 22.

Furthermore, tracking coils 33 are fixedly installed on both sides of the lens barrel 23. The tracking coils 33 are wound in a substantially rectangular shape, and in plan view in FIG. 2, two tracking coils 33 are installed extending in the diametrical direction of the objective lens 22. This tracking coil 33 is connected to the objective lens 2.
2 in the X direction. One of the windings of the tracking coils 33 provided on both sides of the lens barrel 23 is connected to each other, and the two tracking coils 33 are connected in series. The other end 33a of the winding of each tracking coil 33 is soldered to a connecting protrusion 26b at the tip of a bent piece 26a supporting the objective lens 22. As shown in FIG.
A yoke 34 is fixed to the upper surface of. Both end portions 34a of this yoke 34 are bent into a shape that wraps around the outer portions 33a of both tracking coils 33. Further, a magnet 35 is fixed to the yoke 34, and the magnet 35 and the yoke 34 are connected to each other.
A magnetic circuit that traverses the outer portion of the tracking coil 33 is formed by the tip end 34a of the tracking coil 33.

A light transmitting hole 21b and a light receiving hole 21c are formed in the slider 21. Inside the light transmitting hole 21b, a laser diode 41, a diffraction grating 42, a beam splitter 43, a collimating lens 44, and a 1/4
A wavelength plate 45 is housed. These parts are
They are arranged on the line of incidence to the prism 32. Further, a cone cave lens 46, a cylindrical lens 47, and a photodiode 48 are housed in the light receiving hole 21c. These are arranged on the reflection line of the beam splitter 43. A three-beam type optical pickup is constituted by each of the above-mentioned optical members.

Next, the operation of the optical pickup with the above configuration will be explained.

The optical disk 12 is rotationally driven by the turntable 11. In accordance with this, the optical pickup 20 moves away from the position close to the turntable 11, and the optical pickup 20 performs a reproduction operation.

That is, the laser beam emitted from the laser diode 41 is divided into three beams by the diffraction grating 42. The beam further passes through a beam splitter 43, is made into a parallel beam by a collimating lens 44, and passes through a quarter-wave plate 45.
It is sent to the objective lens 22 by the prism 32. The light is focused on the recording surface of the optical disk 12 by the objective lens 22, and three beam spots are formed on the recording surface. The reflected beam from this recording surface is
After passing through the objective lens 22, prism 32, etc.
The beam returns to the beam splitter 43, is reflected in a 90 degree direction, is transmitted through a cone cave lens 46 and a cylindrical lens 47, and is detected by a photodiode 48. By intensity modulating the detection output of the photodiode 48, information pits on the recording surface of the optical disk 12 are read.

During this reproduction operation, the objective lens is finely driven by the correction drive device to perform a correction operation.

A correction operation for focusing the beam spot formed on the recording surface of the optical disk 12 is performed by controlling the current flowing through the focus coil 28. This current is supplied from the connecting protrusion 24b of the upper leaf spring 24, transmitted through the leaf spring 24 itself, and supplied to the focus coil 28 from the connecting protrusion 24a. The intermediate member 25, together with the objective lens 22, is driven in the Y direction by the current flowing in the lateral direction in the focus coil 28 and the magnetic field generated by the magnet 31 and crossing the focus coil 28. This movement is permitted by the deformation of leaf springs 24 and 26.

Further, a correction operation for causing the laser beam irradiated onto the recording surface of the optical disk 12 to follow the information track is performed by controlling the current flowing through the tracking coil 33. This current is supplied from the connecting protrusion 26c of the lower leaf spring 26. Then, the tracking coil 33 is energized from the bent piece 26a of the leaf spring 26 through the connecting protrusion 26b. The objective lens 22 and The lens barrel 23 is slightly driven in the X direction. This movement of the lens barrel 23 is permitted by the deformation of the bent piece 26a.

In addition, in the embodiment shown in the figure, the tracking coil 3
3, the bent piece 26a is linearly fixed to the lens barrel 23, but another holding member may be connected to the lower side of the lens barrel 23, and each of the above members may be fixed to this holding member. .

[Effects of this invention]

As described above, according to the present invention, the intermediate member is supported by four leaf springs, and two of the leaf springs are
A bent piece is formed in the intermediate member, and the holding member for the objective lens is supported by this bent piece, and the coil provided in the intermediate member is energized by two of the leaf springs. The coil mounted on the objective lens holding member was energized through the bent pieces of the other two leaf springs. Therefore, if the four leaf springs supporting the intermediate member are energized, both of the two coils can be energized. Therefore, the lead wires from the outside need only be connected to the four leaf springs mentioned above, and the soldering work can be done in a location facing the outside of the correction drive device, making wiring work more efficient. Become so.

Further, since the end of the leaf spring supporting the intermediate member supports the objective lens holding member and the leaf spring is commonly used, the number of parts can be reduced.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention.
This figure is a plan view showing the power supply mechanism of the optical pickup in a compact disc player, FIG. 2 is a plan view of the optical pickup, and FIG. 3 is a side view thereof. 12... Optical disk, 20... Optical pickup, 21... Slider, 22... Objective lens,
23... Objective lens holding member (lens barrel), 25...
...Intermediate member, 24, 26...Plate spring, 26a...
Bending pieces, 28, 33...Coil.

Claims (1)

[Scope of utility model registration request] An objective lens holding member is further supported on the intermediate member, which is supported by a leaf spring so as to be finely movable, and the intermediate member has a mechanism for driving the intermediate member. In an optical pickup, the intermediate member is supported by four leaf springs, and the objective lens holding member is equipped with a coil for driving the holding member. The coils are electrically connected to two of the leaf springs, and the other two of the leaf springs have their tips bent, and the objective lens holding member A coil energization mechanism for an objective lens, characterized in that the coil is supported by a bent piece, and a coil installed in the objective lens is electrically connected to this bent piece.