JP2856105B2 - Objective lens actuator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an object used in an optical recording / reproducing apparatus such as a compact disc player for reproducing information by condensing a light beam emitted from a light source such as a semiconductor laser on an information recording medium. It relates to a lens actuator.

[0002]

2. Description of the Related Art FIG. 3 shows a conventional objective lens actuator. In FIG. 3, reference numeral 1 denotes a base made of a magnetic metal plate, and magnet holding pieces 2a and 2b projecting in a rectangular parallelepiped shape are provided at both ends of the base 1 so as to face each other. Reference numerals 3a and 3b denote cuboid magnets mounted inside the magnet holding pieces 2a and 2b, respectively, and reference numerals 4a and 4b denote cuboid magnetic path pieces formed by bending a part of the base 1. Pieces 4a, 4
b is provided so as to face the magnets 3a and 3b at a certain interval from the magnets 3a and 3b. Reference numeral 5 denotes a damping member holding substrate mounted outside the magnet holding piece 2b. A concave portion 6 is formed on one surface of the damping member holding substrate 5 as shown in FIG. The damping member 7 is housed. Reference numeral 8 denotes a base disposed outside the damping member holding substrate 5, and the base 8 includes a flexible printed board 8a and a reinforcing plate 8b for reinforcing the flexible printed board 8a. 9a, 9
b, 9c, 9d are wires, and the wires 9a, 9b, 9
One end of each of c and 9d has a through hole 10 formed in the damping member holding substrate 5 and a hole 1 formed in the reinforcing plate 8b.
1. The flexible printed circuit board 8a is inserted into a hole 12 formed in the flexible printed circuit board 8a, and is fixed to the land of the flexible printed circuit board 8a by soldering. Wire rod 9a, 9
An objective lens holder 13 is fixed to the other end of each of b, 9c, 9d, and the objective lens holder 13 is connected to the wires 9a, 9b, 9
It is movably supported by c and 9d. Reference numeral 14 denotes an objective lens 14 held on the upper surface of the objective lens holder 13. A focusing control coil 15 is wound around the outer peripheral surface of the objective lens holder 13, and the magnet 3 on the outer peripheral surface of the objective lens holder 13
A ring-shaped tracking control coil 16 is fixed to a surface facing a and 3b. The above magnet 3
a, 3b, the magnet holding pieces 2a, 2b, the base 1, and the magnetic path pieces 4a, 4b, respectively, constitute a magnetic circuit, and the focusing control coil 15 and the tracking control coil 16 are arranged in a magnetic gap of the magnetic circuit. Have been. The wires 9a, 9b, 9c, 9d are connected to the focusing control coil 15 and the tracking control coil 16, and when a focus error signal is applied to the focusing control coil 15 via the wire, The objective lens holder 13 is the objective lens 1
4 in the optical axis direction, and when a tracking error signal is applied to the tracking control coil 16,
The objective lens holder 13 is driven in a tracking direction orthogonal to the optical axis direction of the objective lens 14 to control the position of the objective lens 14.

FIG. 4 shows a wire 9a, 9b, 9 of the conventional example.
The structure of the fixing part of c, 9d is shown. As shown in FIG. 4, the through-hole 10 formed on the bottom surface of the damping member holding substrate 5 includes a fine hole 10a and a truncated conical hole 10b. The frusto-conical hole 10b has wires 9a, 9b,
9c and 9d are formed so as to be easily inserted into the pores 10a. Reference numeral 17 denotes solder for soldering one end of each of the wires 9a, 9b, 9c, 9d to a land of the flexible printed circuit board 8a.

FIGS. 5 and 6 show a wire rod 9 in the conventional example.
The other end mounting portions of a, 9b, 9c, 9d are shown. 5 and 6, reference numeral 18 denotes a protrusion formed on both side surfaces of the objective lens holder 13. The protrusion 18 has a truncated conical hole 19a and a hole 19b. 20
Is a printed circuit board fixed on the side surface of the objective lens holder 13 with an adhesive, and a square land 21 is formed on the printed circuit board 20. As shown in FIGS. 5 and 6, the wires 9a, 9b, 9c and 9d are inserted into the holes 19a and the holes 19b, and the ends of the wires 9a, 9b, 9c and 9d
1 by soldering, the wires 9a, 9b, 9c,
The other end of 9d is fixed to the damping holding substrate 13. 5 and 6, reference numeral 22 denotes wires 9a, 9b, 9
c and 9 d are solders fixed to the lands 21.

[0005]

However, in the above conventional example, as shown in FIGS. 5 and 6, the wires 9a, 9b,
9c and 9d are fixed to the square land 21 by soldering, so that the wires 9a and 9d are fixed by the surface tension of the solder 22.
There was a problem that b, 9c and 9d were subjected to the force and could not be fixed at the regular positions as indicated by the broken lines. Wires 9a, 9b, 9
When the wires 9a, 9b, 9c, and 9d contact the edges of the holes 19b when the wires 9a, 9b, 9c, and 9d come in contact with the holes 9a, 9b, 9c, and 9d, respectively, the movable lengths of the wires 9a, 9b, 9c, and 9d are fixed. Is shortened, the spring constants of the wires 9a, 9b, 9c, 9d are substantially changed, the primary resonance frequency of the objective actuator is changed, and the light beam spot condensed by the objective lens 14 is converted into an information recording medium. However, there is a problem that the stability of the servo performance for following the surface runout and the eccentricity is deteriorated.

An object of the present invention is to solve the above-mentioned conventional problems, and an object of the present invention is to provide an excellent objective lens actuator which can fix a fixed position of a wire at a regular position.

[0007]

In order to achieve the above object, the present invention provides an objective lens holder provided with a focusing control coil and a tracking control coil and holding an objective lens, and an objective lens holder. A projection formed on the body, a printed circuit board fixed to the objective lens holder, and having a land smaller in width toward the projection, and one end of a wire supporting the objective lens holder held by the objective lens; It is characterized in that it is inserted into a hole in a protruding part of the body and soldered to the land.

[0008]

According to the present invention, when one end of a wire inserted into a hole of a projection of an objective lens holder is soldered to a land of a printed circuit board, the side of the projection having a smaller width is used. Since the solder hardens quickly, the wire is fixed at a proper position.

[0009]

1 and 2 show a wire fixing portion of an objective lens actuator according to an embodiment of the present invention. 1 and 2, reference numeral 18 denotes a protrusion formed on a side portion of the objective lens holder 13, and the protrusion 18 has a hole 19a,
The pore 19b is formed. Reference numeral 20 denotes a printed circuit board fixed to the side of the objective lens holder 13 with an adhesive, and 23 denotes a land of the printed circuit board 20. The shape of the land 23 is such that the width decreases toward the pore 19b.

As shown in FIGS. 1 and 2, wires 9a, 9
When b, 9c, and 9d are inserted into the holes 19a and the fine holes 19b and soldered to the lands 23, the solder 24 is solidified from a portion where the width of the lands 23 is small, so that the wires 9a, 9b, 9c,
9d is located at the center of the hole 19a and the hole 19b, so that the position of the hole 9d does not shift and comes into contact with the edge of the hole 19b.

[0011]

The present invention has the above-described configuration, and when the wire is soldered to the land of the printed circuit board, the wire is attached to a regular position, and the variation in characteristics due to the change in the movable length of the wire is changed. Has the advantage of being able to completely remove.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of an objective lens actuator according to an embodiment of the present invention.

FIG. 2 is a sectional view of a main part of the embodiment.

FIG. 3 is a perspective view of a conventional objective lens actuator.

FIG. 4 is a cross-sectional view of a fixing portion at one end of the conventional wire rod.

FIG. 5 is a sectional view of a fixing portion at the other end of the conventional wire.

FIG. 6 is a sectional view of a fixing portion at the other end of the conventional wire.

[Explanation of symbols]

 9a, 9b, 9c, 9d Wire rod 13 Objective lens holder 18 Projection 19a Hole 19b Pores 20 Printed circuit board 23 Land 24 Solder

Claims (1)

(57) [Claims] 1. An objective lens holding body provided with a focusing control coil and a tracking control coil and holding an objective lens, a projection formed on the objective lens holding body, and fixed to the objective lens holding body. A printed circuit board on which a land having a width smaller toward the protrusion is formed, and one end of a wire supporting the objective lens holder is inserted into a hole of the protrusion of the objective lens holder and soldered to the land. An objective lens actuator characterized by the above-mentioned.