JP2000260044A - Optical pickup - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a movable range limiting mechanism of movable part of an optical pickup, which is not influenced by a light guide route of laser beam, a magnetic circuit, etc. SOLUTION: This is an optical pickup for reading a signal from an optical disk, and a movable range limiting structure for limiting the movable range in the direction of focus of a movable part 10 elastically fixed to a fixing side yoke 20 by suspension wires 11 is characterized in comprising an upper movable range limiting part which is formed integral with a cover part fixed on the top of the yoke 20 and limits the movement of the movable part 10 to side of the optical disk by being abutted to the movable part 10, and a lower movable range limiting part 35 which is formed integral with the cover part as extending in the direction of the bottom of the yoke 20 from the cover part and limits the movement of the movable part to the opposite side of the optical disk by being abutted to the movable part 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical pickup of an optical disk player, and more particularly to a movable range restricting structure for restricting a movable range of a lens holder of the optical pickup in a focus direction.

[0002]

2. Description of the Related Art A main part of an optical pickup included in a conventional optical disk player will be described with reference to FIGS.

FIG. 5 is a front perspective view showing a schematic configuration of a conventional optical pickup. FIG. 6 is a perspective view showing a schematic configuration of a main part of a conventional optical pickup.

An optical pickup provided in an optical disk player includes a lens unit 50, an optical pickup chassis 51 for fixing the lens unit 50, the reflection mirror 90, and the light emitting / receiving unit 91, and the like. The feed mechanism includes a feed screw 92 that moves on a line connecting the outer peripheral direction and a screw hole 93 for the feed screw.

The lens unit 50 includes a movable portion (corresponding to a lens holder) 60, a fixed yoke (corresponding to a chassis) 70 for fixing a damper holder (not shown) for holding a magnet 71 and a suspension wire 61, and a fixed yoke. The lens 70 includes a lens cover 80 and the like provided at the upper end.

The movable portion 60 is elastically held by four suspension wires 61, two on the left and right, two on the left and right, and a coil formed on the outer periphery of the lens 62 of the movable portion 60 and a chassis on the fixed side. The position of the movable section 60 is controlled in the focus direction and the tracking direction during reproduction of the optical disk by a magnetic circuit including a magnet 71 fixed to a yoke 70 formed of a magnetic material such as iron, which also serves as a magnetic member. In this example, the focus direction (vertical direction) of the movable unit 60
A method of restricting the movable range of will be described.

First, a method of controlling the movable range in the focus direction (upward) will be described.

When the movable portion 60 moves toward the optical disk (upward) and exceeds a predetermined movable range, the lens 62 of the movable portion 60 may collide with the surface of the optical disk. Therefore, in order to prevent the collision, the lens cover 80 formed with the upper stopper portion 81 with which the upper surface of the coil bobbin formed on the movable portion 60 comes into contact is formed so as to cover the upper portion of the movable portion 60 (the upper end surface of the yoke 70). Mounting).

The lens cover 80 has a U-shape with a cross section opened downward. An upper stopper portion 81 is formed on an upper surface 83 with which the upper surface of the coil bobbin abuts, and the other portions allow the lens 62 to pass therethrough. It is a light reducing hole 82. Four mounting holes 84 are formed on both sides of the lens cover 80 for mounting the yoke 70 at two locations. The lens cover 80 is formed by pressing using a thin steel plate such as stainless steel.

To mount the lens cover 80, the lens cover 80 is put on the upper end surface of the yoke 70, and the mounting hole 84 formed on the side surface is fitted and fixed to a projection projecting from the side surface of the yoke 70. If a movable stress is applied to the movable portion 60 in the upward direction beyond the predetermined movable range, the upper surface of the coil bobbin is moved to the upper stopper of the lens cover 80 so that the movable portion 60 does not exceed the predetermined movable range. The movable range in the upward direction is regulated by contacting the portion 81.

Next, a method of regulating the movable range in the focus direction (downward) will be described.

When the movable part 60 moves downward and exceeds a predetermined movable range, the lower surface of the movable part 60 is
May collide with a mirror or the like provided below the camera.
Therefore, in order to prevent this collision, a lower stopper 73 is formed by bending a part of the yoke 70 inward (toward the movable part 60) and projecting.

If a movable stress is applied to the movable section 60 in a downward direction beyond a predetermined movable range, the movable section 60 is configured so that the movable section 60 does not exceed the predetermined movable range. The lower surface of the coil bobbin is brought into contact with the lower stopper 73 to regulate the movable range in the lower direction.

[0014]

However, in the above-described movable range restricting structure, a part of the yoke 70 is bent inward to protrude in order to restrict the lower movable range of the movable portion 60.
The lower stopper 73 of the movable part 60 is formed. However, the shape of the yoke 70 and the position of the lower stopper 73 are restricted by the design of the light guide path of the laser beam and the magnetic circuit, and the position of the lower stopper 73 is biased relative to the movable part 60. May be done. In this case, when the movable portion 60 contacts the lower stopper 73, the movable portion 60
The torsional moment is applied to the suspension wire 61 supporting the moving part 60, and the movable part 60 may move in an unstable manner.

In addition, the movable portion 60 is provided with the lower stopper 73.
In particular, an unpleasant collision sound (chatter sound) may be generated in a non-energized state. Also, the movable part 60
In the case where the suspension wire 61 violently collides with the lower stopper 73, an excessive stress is generated in the suspension wire 61, which may cause a problem that the suspension wire 61 is cut.

An object of the present invention is to solve the above-mentioned problem, and an object of the present invention is to provide a structure for restricting a movable range of a lens holder of an optical pickup which is not affected by a laser light guide path, a magnetic circuit, and the like.

[0017]

According to the present invention, there is provided an optical pickup for reading a signal from an optical disk, wherein the lens unit focuses a reading light beam on a recording position of a signal to be read on the optical disk. An optical pickup having a structure fixed to a pickup chassis, wherein the lens unit includes a condenser lens,
A lens holder for holding a lens, to which a driving coil is fixed; and a magnetic circuit for forming a case of the lens unit, wherein a magnet is fixed and the lens operates by the driving coil to move the lens holder. A chassis formed of a magnetic material, a lid fixed to the optical disk side of the chassis, and forming a lens unit case together with the chassis, a suspension wire for elastically fixing the lens holder to the chassis, An upper movable range restricting portion formed integrally with the lid portion and in contact with the lens holder to restrict the movement of the lens holder toward the optical disk; and the lid extending from the lid portion toward the bottom of the chassis. The lens holder is formed integrally with the lens unit and contacts the lens holder to regulate the movement of the lens holder to the side opposite to the optical disk. And it is characterized in that comprising a rectangular movable range restriction section.

Further, the upper movable range restricting portion and the lower movable range restricting portion are formed so as to come into contact with two side ends of the lens unit on the suspension wire supporting side.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS. 1, 2, 3 and 4. FIG.

FIG. 1 is a front perspective view showing a schematic configuration of a main part of an optical pickup. FIG. 2 is a perspective view showing a schematic configuration of a main part of the optical pickup according to one embodiment of the present invention.
FIG. 3 is a diagram showing a lens cover according to the present embodiment.
Is a plan view, and (b) is a front view. FIG. 4 is a transparent side sectional view showing the movable range restricting structure of the movable portion according to the present embodiment.

The optical pickup included in the optical disk player includes a lens unit 17, an optical pickup chassis 43 for fixing the lens unit 17, a reflection mirror, a light receiving / emitting unit, and the like, and an optical pickup chassis 43, which is located between the center of rotation of the optical disk and the outer peripheral direction. And a feed mechanism configured by a feed screw 44 that moves on a line connecting the two and a screw hole 45 for the feed screw.

The lens unit 17 includes a movable portion (corresponding to a lens holder) 10, a fixed yoke (corresponding to a chassis) 20 for fixing a damper holder (not shown) for holding the magnet 21 and the suspension wire 11, and the like, and a fixed side yoke. Lens cover 30 provided at the upper end of yoke 20
And the like.

The movable portion 10 is elastically held by four suspension wires 11 in each of two upper and lower portions on the left and right. The movable unit 10 is a magnetic circuit including a coil formed on the outer periphery of the lens 12 of the movable unit 10 and a magnet 21 fixed to a yoke 20 formed of a magnetic material such as iron which also serves as a fixed chassis. Accordingly, the position adjustment of the movable section 10 in the focus direction and the tracking direction is performed during the reproduction of the optical disk. Therefore, during the adjustment or when vibration is applied from the outside, the movable portion 10 exceeds the proper movable range due to the magnitude of the energy, and the movable portion 10 collides with a component configured in the focusing direction or the tracking direction and is broken. There is a possibility that the movable range must be regulated.

The present embodiment relates to a regulating structure for regulating the movable range of the movable section 10 in the focus direction (vertical direction). The movable range restricting structure will be described below.

When the movable section 10 moves in the direction of the optical disk and exceeds a predetermined movable range, the lens 12 of the movable section 10
May collide with the surface of the optical disk. When the movable section 10 moves downward and exceeds a predetermined movable range, the lower surface of the movable section 10 may collide with a mirror or the like provided below the movable section 10. Therefore, in order to prevent collision in these two directions, a lens cover 30 having a collision prevention function is attached so as to cover the upper end surface of the yoke 20, and the movable portion 10 is regulated within a predetermined movable range.

The lens cover 30 includes an upper cover portion 37 and a lower movable range restricting portion 35 extending from the upper cover portion 37.
Are formed. The upper cover portion 37 has a U-shape whose cross section is open downward, and the upper
An upper stopper portion 31 is formed so that the upper surface 14 of the coil bobbin formed in the movable portion 10 abuts when the optical disk moves in the direction of the optical disk and exceeds a predetermined movable range. The relief hole 32 is provided. The yokes 2 are provided on both side surfaces of the upper cover portion 37.
A total of four holes 34 are formed at two locations for mounting at zero. The lower movable range regulating portion 35 extends downward in the drawing from two positions on the upper surface 33 of the upper cover portion 37 close to the left and right side surfaces in the drawing, and further extends horizontally from the predetermined position toward the movable portion 10. The lower stopper portion 36 is formed so that the lower surface 15 of the bobbin of the movable portion 10 abuts so that the movable portion 10 moves downward and does not exceed a predetermined range. As a material of the lens cover 30, a thin steel plate such as stainless steel is used and formed by press working.

To mount the lens cover 30, the upper cover portion 37 of the lens cover 30 is placed on the upper end surface of the yoke 20, and the holes 34 formed on the side surfaces of the upper cover portion 37 are formed into convex portions protruding from the side surfaces of the yoke 20. Insert and fix.
When a movable stress exceeding a predetermined range is applied to the movable section 10 in the direction of the optical disk, the upper surface 14 of the coil bobbin formed in the movable section 10 is moved so that the movable section 10 does not exceed the predetermined movable range. Is brought into contact with the upper stopper portion 31 to regulate the movable range in the upper direction. In addition, when a movable stress is applied to the movable portion 10 in a downward direction beyond a predetermined movable range, the movable portion 10 is moved below the lower movable range regulating portion 35 so that the movable portion 10 does not exceed the predetermined movable range. The lower surface 15 of the coil bobbin formed in the movable portion 10 is brought into contact with the side stopper portion 36 to regulate the movable range in the downward direction.

As described above, according to the optical pickup of the present embodiment, the movable cover 10 is attached to the lens cover 30.
The upper stopper 31 and the lower stopper 36 which regulate the vertical movable range of the movable part 10 can restrict the vertical movable range of the movable part 10 without increasing the number of components. . Further, the upper stopper portion 31 and the lower stopper portion 36 formed on the lens cover 30 are brought into contact with both ends of the movable portion 10 so as not to affect the light guide path of the laser beam, the magnetic circuit, and the like. Therefore, it is possible to cope with any optical pickup in a wide range.

[0029]

As described above, according to the present invention, it is possible to provide a movable range restricting structure of a lens holder of an optical pickup which is not affected by a light guide path of a laser beam, a magnetic circuit and the like.

[Brief description of the drawings]

FIG. 1 is a front perspective view showing a schematic configuration of a main part of an optical pickup.

FIG. 2 is a perspective view showing a schematic configuration of a main part of the optical pickup according to the embodiment of the present invention.

FIG. 3 is a diagram showing a lens cover according to the embodiment.

FIG. 4 is a front perspective view showing a movable range restricting structure of a movable section according to the present embodiment.

FIG. 5 is a front perspective view showing a schematic configuration of a conventional optical pickup.

FIG. 6 is a perspective view showing a schematic configuration of a main part of a conventional optical pickup.

[Explanation of symbols]

 10 movable part 11 suspension wire 12 lens 14 33 upper surface 15 lower surface 20 yoke 21 magnet Reference numeral 30 Lens cover 31 Upper stopper 32 Reduced hole 34 Hole 35 Lower movable range restrictor 36 Lower stopper part 37 ... Top cover part 43 ... Optical pickup chassis 44 ... Feed screw 45 ... Screw hole 46 ... Reflective mirror 47 ... ..Light receiving and emitting units

Claims (2)

[Claims] 1. An optical pickup for reading a signal from an optical disk, wherein the lens unit for focusing a reading light beam on a recording position of a signal to be read on the optical disk is fixed to a pickup chassis. A condenser lens, a lens holder for holding a lens, to which a driving coil is fixed; and a case for the lens unit, wherein a magnet is fixed to operate the driving coil, and A chassis formed of a magnetic material constituting a magnetic circuit for moving the lens holder, a lid fixed to the optical disk side of the chassis, and forming a lens unit case together with the chassis; and attaching the lens holder to the chassis. A suspension wire to be elastically fixed, and formed integrally with the lid An upper movable range restricting portion that contacts the lens holder and restricts the movement of the lens holder toward the optical disc; and is formed integrally with the lid so as to extend from the lid toward the bottom of the chassis, An optical pickup comprising: a lower movable range restricting portion that contacts the lens holder and restricts the movement of the lens holder toward the side opposite to the optical disk. 2. The apparatus according to claim 1, wherein the upper movable range restricting portion and the lower movable range restricting portion are formed so as to abut on side ends of the lens unit in two directions on a suspension wire supporting side. Optical pickup.