JPH05342607A - Driving device for objective lens - Google Patents

Abstract

PURPOSE:To provide an objective lens driving device with high manufacturing efficiency enabling the winding work of a focusing coil and a tracking coil on a lens holder by an automatic winder from only one side of the lens holder. CONSTITUTION:Restraining parts for restraining the winding ends of the focusing coil 3 and the tracking coil 4 are formed on a printed board 18 mounted on the lens holder. Also, all restraining parts for restraining the starting ends and the terminating ends of windings of the focusing coil 3 and the tracking coil 4, respectively, are arranged on the same surface of the lens holder 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an objective lens driving device for driving an objective lens of an optical pickup device for optically reading out or writing a signal in two orthogonal directions.

[0002]

2. Description of the Related Art As is well known, an optical pickup device for optically reading or writing a signal by using a light beam holds an objective lens in a lens holder and supports the lens holder so that the lens holder can be displaced. An objective lens driving device is provided that drives the objective lens in two axial directions by winding a focusing coil and a tracking coil around the lens holder and sending a control signal to the focusing coil and the tracking coil.
Focusing control for focusing the light beam on the signal surface of the signal recording medium and tracking control for causing the light beam to follow the signal track on the signal surface of the signal recording medium can be performed.

By the way, as disclosed in Japanese Utility Model Publication No. 4-19615, a lens holder is displaceably supported on a frame by four conductive support wires, and a focusing coil and a tracking coil are controlled by using the support wires. An objective lens driving device configured to apply a signal is known.

In such an objective lens driving device, connecting portions connected to the support wires are provided separately on the upper and lower surfaces orthogonal to the optical axis of the objective lens of the lens holder according to the installation position of each support wire. ing. Then, conventionally, a control signal in which each of the supporting wires is energized by relaying each of the connecting portions is supplied to the focusing coil and the tracking coil.

[0005]

As described above, in the objective lens driving device in which the focusing coil and the tracking coil are wound around the lens holder, the winding start end and the winding end of the focusing coil and the tracking coil are predetermined. It is locked at the connection part.
That is, for example, after the winding start end of the focusing coil is locked by winding the coil on one connection portion on the upper surface side protruding to the upper surface of the lens holder, the focusing coil is wound around the lens holder, and finally the lens holder The focusing coil is attached to the lens holder by locking the winding end of the focusing coil by winding the coil around the other connecting portion on the upper surface side, while the lower coil side protruding from the lower surface of the lens holder is attached. After the winding start end of the tracking coil is locked by winding the coil around one connection part, the tracking coil is wound around the lens holder, and finally the tracking is performed by winding the coil around the other connection part on the lower surface side of the lens holder. By locking the winding end of the coil, Perform the mounting of Ngukoiru.

As described above, in the objective lens driving device in which the focusing coil and the tracking coil are wound around the lens holder, conventionally, the winding start ends or the winding ends of the focusing coil and the tracking coil are provided on both sides of the upper surface and the lower surface of the lens holder. Due to the arrangement of the ends, when winding the focusing coil and tracking coil around the lens holder, it is necessary to work from both sides of the surface of the lens holder that is perpendicular to the optical axis of the objective lens, and the coil is automatically wound. The lens holder has to be relocated in the opposite direction to the automatic machine for turning, which complicates the manufacturing machine and increases the manufacturing cost and the manufacturing cost of the focusing coil and tracking coil winding work around the lens holder. It caused efficiency deterioration.

The present invention has been made to solve the above technical problem, and focusing on a lens holder without changing the direction of the lens holder with respect to an automatic machine for automatically winding a coil. It is an object of the present invention to provide an objective lens driving device that can accomplish the winding work of a coil and a tracking coil.

[0008]

SUMMARY OF THE INVENTION According to the present invention, a locking portion for locking a winding end of a coil forming a focusing coil and a tracking coil is formed on a printed circuit board attached to a lens holder, and the focusing coil and the focusing coil are provided. All the locking portions for locking the winding start end and the winding end of the tracking coil are arranged on the same surface side of the lens holder.

[0009]

According to the present invention, the focusing coil and the tracking coil have the winding start end and the winding end on the same surface side of the lens holder, and the coil is automatically wound by the automatic machine from only one side of the lens holder. With this, the focusing coil and the tracking coil can be wound around the lens holder.

[0010]

1 and 2 show an embodiment of the present invention, which is a cross-sectional view and a plan view from the side, respectively. In the figure, 1 is an objective lens, 2 is a lens holder on which the objective lens 1 is mounted, and the objective lens 1 is mounted on the lens holder 2 in the focusing direction (objective lens 1).
Focusing coil 3 for driving in the optical axis direction)
And a tracking coil 4 for driving the objective lens 1 in the tracking direction (arrow direction in FIG. 2).

Reference numeral 5 denotes a magnetic circuit that forms a magnetic field, and includes a pair of permanent magnets 6 and 7, yokes 8 and 9 attached to the permanent magnets 6 and 7, and ends of the yokes 8 and 9, respectively. And the plates 10 and 11 that are erected on the top of the focusing coil 3 and the focusing coil 3 and the tracking coil 4 generate a magnetic flux penetrating within a predetermined range. Therefore, the lens holder 2 can be driven in the focusing direction by supplying a control signal to the focusing coil 3 in a state where the lens holder 2 is arranged at a predetermined position, and a control signal is supplied to the tracking coil 4. By doing so, the lens holder 2 can be driven in the tracking direction.

Reference numeral 12 is a frame to which the magnetic circuit 5 is attached, 13 is four wires for movably supporting the lens holder 2 with respect to the frame 12, and 14 is fixed to one end of the frame 12 by a screw 15. , A fixing member made of a printed circuit board to which one end of each of the four wires 13 is fixed by soldering, 16 is fixed to the other end of the frame 12, and the other ends of the four wires 13 are respectively inserted. Each wire 13 having a hole 17
Is a supporting member for slidably supporting the other end of the.

Each of the wires 13 is two wires on an orthogonal plane orthogonal to the optical axis of the objective lens 1 due to the relationship between the positions of the soldering portions of the fixing member 14 and the holes 17 of the supporting member 16 and the intervals. As shown in FIG. 2, they are installed non-parallel to each other.

By the way, the lens holder 2 is formed with two holes 2a penetrating in the optical axis direction of the objective lens 1 so as to sandwich the objective lens 1, and the trunk portion 18a and the branch portion 18b are respectively formed in the holes 2a. The branched printed circuit boards 18 formed from the
8 is attached to the lens holder 2 as shown in FIG.

As shown in FIG. 3, each printed circuit board 18 has a predetermined wire 1 at each of the upper and lower ends of the trunk portion 18a.
Lands 19a and 19b to which the intermediate portion of 3 is connected are formed.

The printed circuit board 18 is provided with a portion serving as a locking portion for locking the winding start end or winding end of each coil when the focusing coil 3 and the tracking coil 4 are wound (described later). ), A land 20a connected to the land 19a by a pattern is formed in the trunk portion 18a as a portion to be the locking portion, while the branch portion 1
A land 20b connected to the land 19b by a pattern is formed at 8b.

When the printed circuit board 18 is attached to the lens holder 2, both upper and lower ends of the trunk portion 18a project to the upper surface and the lower surface side orthogonal to the optical axis direction of the objective lens 1 of the lens holder 2, respectively. At the same time, the tip of the branch portion 18b is projected to the lower surface side of the lens holder 2. The printed boards 18 arranged on both sides of the objective lens 1 are the same ones. The printed boards 18 are arranged in line symmetry, and the surfaces not on the pattern surface side face each other.

Next, a method of winding the focusing coil 3 and the tracking coil 4 around the lens holder 2 will be described.

First, the land 2 of one printed circuit board 18
The coil is wound several times around the lower end portion of the trunk portion 18a where 0a is formed and locked as the winding start end, and then the coil is wound a predetermined number of times so as to enclose the four side surfaces of the lens holder 2 in a strip shape. Then, next, the one printed circuit board 1
Reference numeral 8 denotes a lens of the focusing coil 3 in which the coil is wound several times around the lower end portion of the trunk portion 18a of the other printed circuit board 18 arranged on the opposite side of the objective lens 1 and locked as the winding end. The winding around the holder 2 is completed.

When the winding of the focusing coil 3 is completed, the coil is wound several times around the tip of the branch portion 18b of the printed board 18 on which the land 20b is formed, and the coil is locked as the winding start end. Then, the objective lens 1 is sandwiched in a direction orthogonal to the winding direction of the focusing coil 3 and the coil is wound a predetermined number of times in a strip shape divided into both sides. Finally, the coil is wound several times around the tip of the branch portion 18b of the other printed circuit board 18 and locked as the winding end,
The winding of the tracking coil 4 around the lens holder 2 is completed.

The winding of the focusing coil 3 and the tracking coil 4 is performed by an automatic machine, and the winding start end and the winding end of the focusing coil 3 and the tracking coil 4 are all on the same side (lower surface side) of the lens holder 2. Therefore, the focusing coil 3 and the tracking coil 4 can be wound without rearranging the lens holder 2 in the opposite direction.

The winding portion of the focusing coil 3 and the tracking coil 4 at which the winding start end and winding end are locked is the lower end portion of the trunk portion 18a or the wide portion of the tip portion of the branch portion 18b. Since it is located at the stepped portion of the boundary of, the locking portions at the winding start end and the winding end of the focusing coil 3 and the tracking coil 4 are prevented from coming off.

Further, since a predetermined land of the printed circuit board 18 is formed at the winding portion of the coil at which the winding start end and the winding end of the focusing coil 3 and the tracking coil 4 are locked, that portion is formed. By soldering, the winding start end and the winding end of the focusing coil 3 and the tracking coil 4 are electrically connected and fixed to the printed circuit board 18, respectively.

By the way, each wire 13 stretched between both ends of the frame 12 has its intermediate portion fixed to the corresponding lands 19a and 19b of each printed circuit board 18 and connected by soldering. Here, as for the land of each printed circuit board 18 to which each wire 13 is connected, the land 19a of one printed circuit board 18 is connected to the winding start end of the focusing coil 3.
The land 19a of the other printed circuit board 18 is connected to the winding end of the focusing coil 3
In addition, the land 19b of one printed circuit board 18 is connected to the winding start end of the tracking coil 4.
b, the land 19b of the other printed circuit board 18 is connected to the winding end of the tracking coil 4
Are connected to each other.

Each wire 13 is composed of a conductive metal wire made of phosphor bronze, supports the lens holder 2 in a displaceable manner, and receives control signals for focusing and tracking, respectively, from the focusing coil 3 and the focusing coil 3, respectively. It plays a role of supplying the tracking coil 4.

That is, the focusing control signal, which flows from one of the two wires 13 arranged on the lower surface side of the lens holder 2, relays the pattern connecting the lands 19a and 20a of the one printed circuit board 18, and then the focusing is performed. Since it flows out to the other of the two wires 13 through the coil 3, the focusing control signal is supplied to the focusing coil 3 by using the two wires 13 as positive and negative transmission lines of the focusing control signal, respectively. Can be supplied.

Further, the tracking control signal that flows in from one of the two wires 13 arranged on the upper surface side of the lens holder 2 is a land 19 of one printed circuit board 18.
After relaying the pattern connecting b and 20b, it flows out to the other of the two wires 13 via the tracking coil 4, so that the two wires 13 are used as positive and negative transmission lines of the tracking control signal, respectively. By using it, the tracking control signal can be supplied to the tracking coil 4.

The focusing control signal and the tracking control signal are supplied to the focusing coil 3 and the tracking coil 4, respectively, through the printed circuit boards which constitute the fixing member 14.

[0029]

As described above, according to the present invention, all locking portions for locking the winding start end and winding end of the focusing coil and the tracking coil are arranged on the same side of the lens holder. With this configuration, the focusing coil and tracking coil can be wound by an automatic machine from only one side of the lens holder without rearranging the lens holder in the opposite direction. The advantage is that the increase can be suppressed and the production efficiency can be improved.

[Brief description of drawings]

FIG. 1 is a side sectional view showing an embodiment of the present invention.

FIG. 2 is a plan view showing the objective lens driving device of FIG.

FIG. 3 is an enlarged view of a printed circuit board for explaining a main part of the present invention.

[Explanation of symbols]

 2 Lens Holder 3 Focusing Coil 4 Tracking Coil 13 Wire 18 Printed Circuit Board 18a Trunk 18b Branch

Claims (1)

[Claims] 1. In an objective lens driving device in which a focusing coil and a tracking coil are wound around a lens holder on which an objective lens is mounted, a lock for locking winding ends of coils forming the focusing coil and the tracking coil. Parts are formed on a printed circuit board attached to the lens holder, and all locking parts for locking the winding start end and the winding end of the focusing coil and the tracking coil are arranged on the same surface side of the lens holder. An objective lens driving device having a configuration.