JP2002056551A - Optical driving device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical driving device capable of attaining miniaturization and reduction in weight, displaying an excellent operational characteristic and raising a high order resonant frequency. SOLUTION: In the optical driving device 1 wherein a lens supporting body 8 which supports an objective lens 7, also has focusing coils 9 and tracking coils 10 and is supported so as to displace in the focusing direction and in the tracking direction by a supporting mechanism part 3 and a magnet which is faced to the focusing coils 9 and the tracking coils 10 of the lens supporting body 8 are provided, and wherein the lens supporting body 8 is driven in the focusing direction and in the tracking direction by an electromagnetic action between the focusing coil 9/the tracking coil 10 and the magnet, both focusing coils 9 and tracking coils 10 are pattern formed on one substrate. Thus, miniaturization and reduction in weight are attained, the excellent operational characteristic is displayed and the high order resonant frequency is raised.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical system driving apparatus, and more particularly, to an optical system suitable for use in an optical information recording / reproducing apparatus for optically recording or reproducing information on a recording medium such as an optical disk. The present invention relates to a system driving device.

[0002]

2. Description of the Related Art Generally, in order to record or reproduce information on an optical disk or the like by an optical information recording / reproducing apparatus, an objective lens of an optical system driving device is held so that a light spot appropriately follows an information track of the optical disk or the like. It is necessary to control the lens holder.

For this reason, conventionally, as an optical system driving device, a lens holder holding an objective lens is supported by a support mechanism so as to be displaceable in a focus direction parallel to the optical axis and a tracking direction orthogonal to the focus direction. ,
The lens support is driven in a focus direction and a tracking direction by an electromagnetic action of a focus coil and a tracking coil provided on the lens holder by a winding process or a press forming process, and a permanent magnet disposed opposite to the focus coil and the tracking coil. Like that.

[0004]

However, in the case of the optical system driving device having the above-mentioned structure, since the focus coil and the tracking coil are both formed by winding or press forming, variations in dimension are caused. There has been a problem that the magnetic characteristics cannot be largely uniformed and it is difficult to reduce the size and weight.

Further, the above-mentioned focus coil and tracking coil have a large thickness, and when they are inserted into a magnetic circuit, there is a problem that a magnetic gap becomes large and a reduction in magnetic flux density causes a decrease in sensitivity.

Further, since the focus coil and the tracking coil are attached to the lens holder,
There is also a problem that the rigidity of the lens holder is reduced and the higher-order resonance frequency cannot be increased.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an optical system driving device which has an improved structure, can be reduced in size and weight, exhibits excellent operating characteristics, and can increase a high-order resonance frequency. It is.

[0008]

According to the present invention, there is provided a lens support which holds an objective lens, has a focus coil and a tracking coil, and is supported by a support mechanism so as to be displaceable in a focus direction and a tracking direction.
An optical system driving device including a magnet opposed to a focus coil and a tracking coil of the lens support, and driving the lens support in a focus direction and a tracking direction by an electromagnetic action of the focus coil and the tracking coil. The focus coil and the tracking coil are characterized by being patterned on the same substrate, and the focus coil and the tracking coil are formed via an insulating layer. Is what you do.

[0009]

According to the optical system driving device having the above-described structure, the focus coil and the tracking coil, which are provided on the lens holder and exhibit an electromagnetic effect, are formed on the same substrate by patterning, or an insulating layer is provided between them. As a result, the magnetic characteristics can be uniformized, and the size and weight can be reduced.

In addition, the focus coil and the tracking coil having such a configuration have a reduced thickness, and when they are inserted into a magnetic circuit, the magnetic gap can be reduced, so that the magnetic flux density is increased and the operation of the optical system driving device is improved. High sensitivity can be achieved.

Further, since the focus coil and the tracking coil having such a configuration are attached to the lens holder, the rigidity of the lens holder can be increased and the higher-order resonance frequency can be increased.

[0012]

Embodiments of the present invention will be described below in detail.

An optical system driving apparatus 1 shown in FIG. 1 comprises a flat base 2, a rectangular parallelepiped support 5 constituting a support mechanism 3 provided on an end of the base 2, and a support 5, a lens support 8 for holding an objective lens 7 attached to a total of four spring members 6 projecting in the horizontal direction, and the lens support 8
A focus coil 9 and a tracking coil 10 each of which is a thick film coil attached to both end surfaces of the lens support 8 and the same shape arranged on the base 2 near both end surfaces of the lens support 8 in the tracking direction with respect to the lens support 8. Are provided with a pair of yokes 13 each having a small width, and permanent magnets 11 and 12 which are vertically arranged with respect to each of the yokes 13 and which are attached in a state of being close to the lens support 8, respectively.

Each of the upper permanent magnets 11 has an N pole facing the tracking coil 10 side. Also,
Each of the lower permanent magnets 12 has its S pole facing the lens support 8 side.

Here, an example of manufacturing the focus coil 9 and the tracking coil 10 using the thick film coil will be described in detail with reference to FIGS.

To manufacture the focus coil 9,
First, as shown in FIG. 3, a rectangular substrate 21 made of alumina (having a thickness of about 20 μm) 21 is prepared, and a width of 100 to 150 μm and a thickness of 5
A pattern P1 made of a conductor such as copper is formed in a rectangular spiral shape by a printing method of about 20 μm.

Next, as shown in FIG. 5, an insulating layer 22 using a low melting point glass is applied by printing on the pattern P1 to cover the pattern P1. At this time, the connection hole 23 is formed only above the inner end of the pattern P1.

Next, as shown in FIG. 6, a pattern P2 made of a conductor such as copper and formed by a printing method and having a width of 100 to 150 μm and a thickness of 5 to 20 μm is also formed on the insulating layer 22 in a square spiral shape. . At this time, the inner end of the pattern P2 is connected to the inner end of the pattern P1 via the hole 23.

Further, as shown in FIG.
An insulating layer 24 made of low-melting glass is applied by printing to cover the pattern P2.

Thus, the focus coil 9 can be obtained.

The outer end regions of the patterns P1 and P2 are slightly larger as shown in FIGS. 4 and 6, and are used for soldering lead wires (not shown).

A tracking coil 10 is formed on the focus coil 9.

That is, first, as shown in FIG. 8, the upper left corner on the focus coil 9 has a width of 100 to 150 μm.
A pattern P3 made of a conductor such as copper and having a thickness of 5 to 20 μm is formed in a rectangular spiral shape by a printing method.

Next, as shown in FIG. 9, an insulating layer 32 made of low-melting glass is applied by printing on the pattern P3 to cover the pattern P3. At this time, the connection hole 33 is formed only above the inner end of the pattern P3.

Next, as shown in FIG. 10, the insulating layer 32 has a width of 100 to 150 μm and a thickness of 5 to 20 μm.
A pattern P4 made of a conductor such as copper is formed in a square spiral shape by the printing method described above. At this time, the inner end of the pattern P4 is connected to the inner end of the pattern P3 via the hole 33.

Further, as shown in FIG.
An insulating layer 34 made of low-melting glass is applied by printing on the substrate 4 to cover the pattern P4.

In this way, the tracking coil 10 can be formed on the focus coil 9. The method of manufacturing the tracking coil 10 formed at the upper right corner on the focus coil 9 is exactly the same as that described above.

The outer end regions of the patterns P3 and P4 are slightly larger as shown in FIGS. 8 and 10, and are used for soldering lead wires (not shown).

The focus coil 9 and the tracking coil 10 manufactured as described above are bonded to the respective end faces of the lens support 8 using an adhesive as shown in FIG.

According to the optical system driving device 1 having the above-described configuration, since both the focus coil 9 and the tracking coil 10 provided on the lens holder 8 and exhibiting the electromagnetic action are formed of the thick film coils, the dimensions are thin and uniform. Therefore, the magnetic characteristics can be made uniform, and the size and weight can be reduced.

It should be noted that, of the focus coil 9 and the tracking coil 10, only the tracking coil 10 may be a thick-film coil, or conversely, only the focus coil 9 may be a thick-film coil.

Further, since the thickness of the focus coil 9 and the tracking coil 10 made of the thick film coil described above is much thinner than that of the conventional focus coil and tracking coil, they are used in the magnetic circuit of the optical system driving device 1. When it is inserted, the magnetic gap can be reduced, thereby increasing the magnetic flux density between the focus coil 9 and the tracking coil 10 and the permanent magnets 11 and 12, and making the operation of the optical system driving device 1 highly sensitive.

Further, since the focus coil 9 and the tracking coil 10 of the thick film coil are attached to the lens holder 8, the rigidity of the lens holder 8 becomes larger than that of the conventional example. Higher order resonance frequencies can also be increased.

FIG. 12 shows another embodiment of the present invention. The optical system driving device 1A shown in FIG. A pair of narrow yokes 15 are erected, and a permanent magnet 11 is arranged above each of the yokes 15 such that the N pole faces the tracking coil 10.
Is cut out in a rectangular shape along the focus direction and the same width as the width of the permanent magnet 11 in the tracking direction, and a pair of rectangular parallelepiped internal yokes 41 and 42 are formed therein.
Is a feature of the arrangement.

With this optical system driving device 1A, it is possible to exhibit the same operational effects as in the case of the optical system driving device 1.

The present invention is not limited to the embodiment described above, and various modifications can be made within the scope of the invention.

[0037]

According to the present invention described in detail above, a focus coil and a tracking coil which exert an electromagnetic action provided on a lens holder are patterned on the same substrate, or an insulating layer is provided between them. The magnetic characteristics can be uniformized, the size and weight can be reduced, and when inserted into a magnetic circuit, the magnetic gap can be reduced, increasing the magnetic flux density and increasing the sensitivity of the operation of the optical system driving device. Further, it is possible to provide an optical system driving device capable of increasing the rigidity of the lens holder and increasing the higher-order resonance frequency.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an apparatus according to an embodiment of the present invention.

FIG. 2 is an enlarged perspective view of a lens holder of the embodiment device of the present invention.

FIG. 3 is a manufacturing process diagram of a focus coil in the apparatus according to the embodiment of the present invention.

FIG. 4 is a manufacturing process diagram of a focus coil in the apparatus according to the embodiment of the present invention.

FIG. 5 is a manufacturing process diagram of a focus coil in the apparatus according to the embodiment of the present invention.

FIG. 6 is a view showing a manufacturing process of a focus coil in the apparatus according to the embodiment of the present invention.

FIG. 7 is a manufacturing process diagram of a focus coil in the apparatus according to the embodiment of the present invention.

FIG. 8 is a manufacturing process diagram of a tracking coil in the apparatus according to the embodiment of the present invention.

FIG. 9 is a manufacturing process diagram of a tracking coil in the apparatus according to the embodiment of the present invention.

FIG. 10 is a manufacturing process diagram of a tracking coil in the apparatus according to the embodiment of the present invention.

FIG. 11 is a manufacturing process diagram of a tracking coil in the apparatus according to the embodiment of the present invention.

FIG. 12 is a perspective view showing an apparatus according to another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Optical system drive 2 Base 3 Support mechanism 7 Objective lens 8 Lens support 9 Focus coil 10 Tracking coil 11 Permanent magnet 12 Permanent magnet

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Mitsuru Kinouchi 1-1-13 Nihonbashi, Chuo-ku, Tokyo Inside TDK Corporation (72) Katsuto Nagano 1-13-1 Nihonbashi, Chuo-ku, Tokyo T F-term in DC Corporation (reference) 5D118 AA01 AA13 AA23 DC02 EA02 EB11 EB17 EC05 EC10

Claims (2)

[Claims] 1. A lens support that holds an objective lens, includes a focus coil and a tracking coil, and is supported by a support mechanism so as to be displaceable in a focus direction and a tracking direction, and a focus coil and a tracking coil of the lens support. In the optical system driving device having a magnet opposed to the, and driving the lens support in the focusing direction and the tracking direction by the electromagnetic action of the focus coil and the tracking coil, the focus coil and the tracking coil,
An optical system driving device, wherein a pattern is formed on the same substrate. 2. The optical system driving device according to claim 1, wherein the focus coil and the tracking coil are formed via an insulating layer.