JPH11339275A - Optical pickup device and optical disk device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical pickup device capable of fully securing the movable range of an objective lens drive mechanism. SOLUTION: An optical lens drive mechanism 20, which performs the positioning of an objective lens L arranged opposite to an optical disk, is equipped with a first and a second holding parts 21a, 21b, that are provided at different positions along the axial direction of the objective lens L and with a leaf spring, that is attached to the objective lens drive mechanism 20 for supporting it elastically and comprises a first supporting part 32, which is arranged opposite to the first holding part 21a and presses it to the optical base 10 side within a first stroke range S1, and with a second supporting part 33 which is arranged opposite to the second holding part 21b and presses it to the optical base 10 side in a second stroke range S2 which is different from the first stroke range S1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an optical pickup device and an optical disk device for recording and reproducing data on and from an optical disk as a recording medium.

[0002]

2. Description of the Related Art In an optical pickup device incorporated in a conventional optical disk device, an objective lens driving mechanism for supporting an objective lens on an optical base is positioned while being biased by a leaf spring. That is, the optical position of the objective lens is adjusted after the objective lens drive mechanism is incorporated into the optical base, and then the objective lens is fixed. Therefore, the movable range in the radial direction and the tangential direction of the objective lens driving mechanism with respect to the optical base is ensured by the leaf spring.

[0003]

The above-mentioned conventional optical pickup device has the following problems. That is, when the movable range necessary for position adjustment exceeds the elastic range of the leaf spring, the leaf spring in the axial direction of the objective lens is plastically deformed. For this reason, the leaf spring cannot generate a sufficient urging force in the axial direction of the objective lens, and cannot support the objective lens driving mechanism. Therefore, the movable range is limited. Accordingly, an object of the present invention is to provide an optical pickup device and an optical disk device that can sufficiently secure a movable range of an objective lens driving mechanism.

[0004]

In order to solve the above-mentioned problems and to achieve the object, an invention according to claim 1 is an optical base on which a light source and a light detecting unit are mounted, and an object arranged to face an optical disk. An objective lens driving mechanism for displacing a lens, a plate spring having one end fixed to the optical base and the other end elastically supporting the objective lens driving mechanism; A first holding portion and a second holding portion provided at different positions along the axial direction of the objective lens, wherein the leaf spring is arranged to face the first holding portion, and is provided in a predetermined direction along the axial direction. A first support portion for urging the first holding portion toward the optical base in a first stroke range, and a first support portion disposed opposite to the second holding portion, along the axial direction and different from the first stroke range; Second It said second holding portion in the stroke range was set to and a second support portion for biasing the optical base side.

According to a second aspect of the present invention, in the first aspect of the invention, the leaf spring biases the objective lens driving mechanism in a direction orthogonal to the axial direction of the objective lens.

According to a third aspect of the present invention, in the first aspect of the invention, the leaf spring includes a cover for preventing foreign matter from entering the objective lens driving mechanism.

According to a fourth aspect of the present invention, there is provided an optical base on which a light source and a light detecting unit are mounted, an objective lens driving mechanism for displacing an objective lens disposed to face an optical disk, and one end of which is connected to the optical base. A leaf spring fixed at the other end and elastically supported by being attached to the objective lens driving mechanism, and the other end of the leaf spring defines a predetermined first position of the objective lens driving mechanism. A first support that presses the optical base side; and a second support that presses a predetermined second position of the objective lens driving mechanism toward the optical base. The first support and the second support The range of generation of the urging force for the objective lens driving mechanism in the axial direction of the objective lens differs from that of the support portion.

According to a fifth aspect of the present invention, an optical pickup device having a light source for emitting a laser beam reproduces or records a signal by irradiating the optical disk with a light, and the light source and the photodetector are attached to the optical pickup device. An optical base, an objective lens driving mechanism for displacing an objective lens disposed to face the optical disk, and a leaf spring having one end fixed to the optical base and the other end elastically supporting the objective lens driving mechanism. Wherein the objective lens driving mechanism includes a first holding portion and a second holding portion provided at different positions along the axial direction of the objective lens, and the leaf spring is provided on the first holding portion. Are arranged facing each other,
A first supporting portion for urging the first holding portion toward the optical base in a predetermined first stroke range along the axial direction, and a first supporting portion arranged to face the second holding portion, and along the axial direction; A second support portion for urging the second holding portion toward the optical base in a second stroke range different from the first stroke range is provided.

[0009] As a result of taking the above measures, the following effects occur. That is, according to the first aspect of the invention, the leaf spring is disposed to face the first holding portion, and biases the first holding portion toward the optical base in a predetermined first stroke range along the axial direction. A first support portion and a second support portion that is disposed to face the second holding portion and that urges the second holding portion toward the optical base in a second stroke range different from the first stroke range along the axial direction. I prepared for it,
The biasing force of the leaf spring functions over a first stroke range and a second stroke range. Therefore, the movable range of the objective lens driving mechanism can be widened.

According to the second aspect of the present invention, since the leaf spring biases the objective lens driving mechanism in a direction orthogonal to the axial direction of the objective lens, the leaf spring is applied to the objective lens driving mechanism by one leaf spring. Forces can act in two directions.

According to the third aspect of the present invention, since the cover for preventing foreign matter from entering the objective lens driving mechanism is provided, foreign matter is prevented from entering the objective lens driving mechanism without using a separate member. can do.

According to the invention described in claim 4, the other end of the leaf spring presses a predetermined first position of the objective lens driving mechanism toward the optical base, and the other end of the objective lens driving mechanism. A second support portion for pressing a predetermined second position toward the optical base, wherein the first support portion and the second support portion have an urging force generation range for the objective lens driving mechanism in the axial direction of the objective lens. Due to the difference, the biasing force of the leaf spring is generated in different ranges. Therefore, the movable range of the objective lens driving mechanism can be widened.

According to the fifth aspect of the present invention, the leaf spring is disposed to face the first holding portion and urges the first holding portion toward the optical base in a predetermined first stroke range along the axial direction. A first support portion, and a second support portion.
A second support portion that urges the second holding portion toward the optical base in a second stroke range different from the first stroke range along the axial direction is provided, so that the biasing force of the leaf spring is the first. It functions over the stroke range and the second stroke range. Therefore, the movable range of the objective lens driving mechanism can be widened.

[0014]

FIG. 1 is a diagram showing a main part of an optical disk device 1 having an optical pickup device 3 in which an objective lens driving mechanism 20 according to an embodiment of the present invention is incorporated. A first optical disk (DVD) and a second optical disk (CD) having different substrate thicknesses are selectively mounted on the disk rotation drive unit 2 of the optical disk device 1.

The optical pickup device 3 irradiates a laser beam to the information recording surface of the optical disk mounted thereon. The optical pickup device 3 is reciprocally movable in the radial direction of the optical disk so as to face the information recording surface of the mounted disk at an interval (in the directions indicated by arrows W1 and W2).
Is to be guided to.

The optical pickup device 3 includes an optical base 10
It has. As shown in FIG. 2, a first laser beam (wavelength 650 nm) for outputting a semiconductor laser beam is provided on the optical base 10.
And a unit 12 in which a second light source that outputs semiconductor laser light (wavelength 780 nm) and a photodetector are integrated. Further, a cube-shaped beam splitter 13 is provided on the optical base 10. The beam splitter 13 includes the laser light from the unit 11 and the unit 12.
From the same output direction on the outward path (the objective lens L
Side) and output. Further, the beam splitter 13 branches and guides the reflected light on the return path, which has returned in the reverse direction from the same output direction, to the units 11 and 12 that have emitted the respective reflected lights.

On the other hand, reference numeral 20 in FIG.
Reference numeral 30 denotes a leaf spring. Objective lens drive mechanism 20
As shown in FIG. 3, a base 21 elastically supported by a leaf spring 30 and an arrow F in FIG.
a lens bobbin 22 that is provided to be swingable in the o and Tr directions and holds the objective lens L. Lens bobbin 2
2 is provided with a focusing coil 23 and a tracking coil (not shown).

The base body 21 includes (a) and (b) of FIG.
As shown in (1), a first holding portion 21a and a second holding portion 21b are provided, and are provided so that the positions of the objective lenses L in the axial direction C are different from each other.

As shown in FIG. 3, the leaf spring 30 has a main body portion (one end portion) 31 screwed to the optical base 10, a first support portion 32 and a second support portion extending from the main body portion 31. 33, and the first support portion 32 includes the first holding portion 2
1a, and the second support portion 33 is
b.

On the other hand, the position of the objective lens driving mechanism 20 is adjusted as shown in FIGS.
4A illustrates a state in which the base body 21 has moved upward from the reference position H, and FIG. 4B illustrates a state in which the base body 21 is at the reference position H. 4C illustrates a state in which the base body 21 has moved downward from the reference position H.

That is, in the case where the positional relationship between the leaf spring 30 and the base body 21 is as shown in FIG. 4A, the first support portion 32 is moved from the elastic limit to a position corresponding to a state released from the elastic limit. When the urging force of the first support portion 32 acts on the first holding portion 21a in one stroke range S1, the objective lens driving mechanism 20 is supported on the optical base 10. Further, when the position of the objective lens driving mechanism 20 is adjusted and the objective lens driving mechanism 20 has a positional relationship with the leaf spring 30 as shown in FIG. The urging force of the second support portion 33 acts on the second holding portion 21b in the second stroke range S2 from the position corresponding to the position (a) to the position corresponding to the released state of the second support portion 33.

Therefore, the range in which the urging force of the leaf spring 30 functions, that is, the movable range S of the objective lens driving mechanism 20 is S1 + S2, which is wider than that in the case where a normal leaf spring is used.

The optical pickup device 20 configured as above operates as follows. That is, the unit 11
Is transmitted through a beam splitter 13, transmitted through a collimator lens (not shown), is raised by a reflection mirror (not shown), passes through the objective lens L, and is transmitted to the information recording surface of the optical disk. Form spots. The light reflected from the information recording surface of the optical disk passes through the return path of the objective lens L, the reflection mirror, and the collimator lens, and enters the beam splitter 13.

The beam splitter 13 guides the reflected light on the return path, which has returned in the backward direction, to the unit 11 or unit 12 from which the reflected light has been emitted, and guides the laser light to the respective photodetectors.

On the other hand, the objective lens driving mechanism 20 supplies a control current to the focusing coil 23 or the tracking coil, controls the electromagnetism, and controls the position of the objective lens L. This position control is physically performed in a tracking direction indicated by an arrow Tr and a focusing direction indicated by an arrow Fo in FIG.

The present invention is not limited to the above embodiment. That is, in the above-described embodiment, the objective lens driving mechanism is biased by the two support portions having different bias ranges, but three or more support portions may be provided. In addition, it goes without saying that various modifications can be made without departing from the spirit of the present invention.

[0027]

According to the present invention, the biasing force of the leaf spring functions over the first stroke range and the second stroke range. For this reason, when attaching to the optical base of the objective lens drive mechanism, it is possible to widen the attachment adjustment range.

[Brief description of the drawings]

FIG. 1 is a plan view showing a main part of an optical disk device according to an embodiment of the present invention.

FIG. 2 is an exemplary perspective view showing an optical pickup device incorporated in the optical disc device;

FIG. 3 is a plan view showing a main part of the optical pickup device.

FIG. 4 is an explanatory view showing an operation of a leaf spring incorporated in the optical pickup device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Optical disk apparatus 2 ... Disk rotation drive part 3 ... Optical pickup apparatus 10 ... Optical base 11, 12 ... Unit 20 ... Objective lens drive mechanism 30 ... Leaf spring 21 ... Base body 21a ... First holding part 21b ... Second holding part 22 lens bobbin 23 focusing coil 30 leaf spring 31 body 32 first support 33 second support

Claims (5)

[Claims] An optical base on which a light source and a light detecting unit are mounted; an objective lens driving mechanism for displacing an objective lens disposed to face an optical disk; one end of which is fixed to the optical base; A leaf spring that elastically supports the objective lens driving mechanism, wherein the objective lens driving mechanism includes a first holding unit and a second holding unit provided at different positions along the axial direction of the objective lens. A first support portion disposed opposite to the first holding portion, for urging the first holding portion toward the optical base in a predetermined first stroke range along the axial direction; A second support portion disposed opposite to the second holding portion and configured to urge the second holding portion toward the optical base in a second stroke range different from the first stroke range along the axial direction. Optical pickup device characterized in that is e. 2. The optical pickup device according to claim 1, wherein the leaf spring biases the objective lens driving mechanism in a direction orthogonal to an axial direction of the objective lens. 3. The optical pickup device according to claim 1, wherein the leaf spring includes a cover for preventing foreign matter from entering the objective lens driving mechanism. 4. An optical base on which a light source and a light detecting unit are mounted, an objective lens driving mechanism for displacing an objective lens arranged to face an optical disk, one end of which is fixed to the optical base, and the other end of which is connected to the optical base. A leaf spring for elastically supporting the objective lens driving mechanism, wherein the other end of the leaf spring presses a predetermined first position of the objective lens driving mechanism toward the optical base; A second support portion for pressing a predetermined second position of the objective lens driving mechanism toward the optical base; wherein the first support portion and the second support portion are arranged in the axial direction of the objective lens. An optical pickup device, wherein a range of generation of an urging force for an objective lens driving mechanism is different. 5. An optical disk device in which an optical pickup device having a light source for emitting a laser beam reproduces or records a signal by irradiating an optical disk with an optical base. An objective lens driving mechanism for displacing an objective lens to be disposed; a leaf spring having one end fixed to the optical base and the other end elastically supporting the objective lens driving mechanism; The mechanism includes a first holding portion and a second holding portion provided at different positions along the axial direction of the objective lens, and the leaf spring is disposed to face the first holding portion, and is arranged in the axial direction. A first support portion for urging the first holding portion toward the optical base in a predetermined first stroke range along the first holding portion; Together along the direction, the optical disk apparatus characterized by comprising a second support portion for biasing the second holding portion in the optical base side at a different second stroke range from the first stroke range.