JP3434673B2 - Optical pickup device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical pickup for optically writing (recording) and reading (reproducing) information on a disc-shaped storage medium (hereinafter referred to as an optical disc) such as a compact disc (CD) or an optical disc. Regarding the device.

[0002]

2. Description of the Related Art Conventionally, an optical pickup device for recording and reproducing on an optical disc collects a laser beam emitted from a semiconductor laser in an optical integrated element as a minute spot on a recording surface of the optical disc by a reflecting mirror and an objective lens. It is configured so that the reflected light reflected from the optical disc is guided to the photoelectric conversion unit in the optical integrated device by the objective lens and the reflection mirror at the time of reproduction to record information by the intensity of the reflected light. There is.

If the optical disc on which information is recorded or reproduced has a warp or eccentricity, a vertical movement of the optical disc causes a focus shift or a tracking shift due to eccentricity when recording or reproducing information.

Therefore, in the past, in order to correct these deviations, the objective lens driving device moves the objective lens parallel to the optical axis direction (focus direction) F perpendicular to the recording / reproducing surface of the optical disk and the recording / reproducing surface. The drive is controlled in two directions of the radial direction (tracking direction) T.

On the other hand, in recent years, there has been a demand for smaller and lighter optical pickup devices due to the portable use of CD players and the like, and in order to meet these demands, for example, JP-A-4-313825 and JP-A-5-73934 are required. A small and lightweight optical pickup device has been proposed in gazettes and the like.

FIGS. 6 to 9 show a typical example of a conventional optical pickup device. In these figures, reference numeral 1 is an optical base, which is an access spindle provided parallel to the tracking direction T of the optical disk 2. Both ends are slidably supported between the access shaft 3 and the sub shaft 4 for access, and are movable in an access direction Ac parallel to the tracking direction T by an access motor (not shown).

An optical integrated device provided with a semiconductor laser which serves as a light source and a photoelectric conversion portion (both not shown) for photoelectrically converting the reflected light from the optical disk 2 at the end of the optical base 1 on the side of the access sub-axis 4. The element 5 is attached via a holding spring 6.

On the optical table 1 in the vicinity of the optical integrated device 5, a steady rest 7 for preventing the optical table 1 from vibrating even if a shock or vibration is applied when the optical table 1 moves in the access direction Ac. Is provided.

The steady rest spring 7 is formed of a leaf spring, one end side of which is fixed on the optical stand 1 by a set screw 7a, and the other end side thereof has a substantially V-shape as shown in FIG. It is bent and its tip is pressed against the access auxiliary shaft 4 from below.

An optical integrated device 5 is provided at the center of the optical table 1.
Laser light emitted from the semiconductor laser of the objective lens 9
The reflection mirror 10 that guides the laser light reflected to the side and reflected from the optical disk 2 to the photoelectric conversion unit of the optical integrated device 5.
Are installed at an angle of 45 ° with respect to the optical axis of the objective lens 9.

An objective lens driving device 11 is installed above the reflection mirror 10.

The objective lens driving device 11 includes an optical table 1
It has a base 11a placed thereon, and a frame-shaped frame 11b is fixed to the base 11a.

A lens holder 9a to which an objective lens 9 is attached is provided at the center of the frame 11b.

One end of, for example, four metal wires 13 which are parallel to each other is fixed to the lens holder 9a.
The other end of 3 is fixed to the frame 11b, and the elasticity of the metal wire 13 holds the objective lens 9 movably in the vertical and horizontal directions.

A pair of magnet bodies 14 are attached to both ends of the lens holder 9a, and the frame 1
A focus coil 15 and a tracking coil 16 are provided on the 1b side so as to face the magnet bodies 14.

The operation of the conventional optical pickup device having the above-described structure will be described. When information is recorded on the optical disc 2, the laser light emitted from the semiconductor laser of the optical integrated device 5 is reflected by the reflecting mirror 10 and the objective. When the lens 9 collects and records as a small spot on the recording / reproducing surface of the optical disk 2 and reproduces the light, the reflected light from the optical disk is transferred to the photoelectric conversion unit of the optical integrated device 5 by the objective lens 9 and the reflecting mirror 10. Then, the signal is converted into an electric signal by the photoelectric conversion unit and reproduced.

If the optical disc 2 has a warp or an eccentricity, and a focus shift or a tracking shift occurs during recording or reproduction, a detecting means (not shown) detects the shift and the focus coil 15 and the tracking so as to correct the shift. A control signal is applied to the coil 16.

As a result, the objective lens 9 is driven in the focus direction F and the tracking direction T, and the focus shift and the tracking shift are corrected.

[0019]

However, in the above-mentioned conventional optical pickup device, the pressing spring 6 for fixing the optical integrated element 5 to the optical base 1 and the steady rest spring 7 for suppressing the vertical vibration of the optical base 1 are provided. Since it is a separate body, a large amount of space is required to install these springs 6 and 7, which is an obstacle to downsizing the optical pickup device.

Further, since the number of parts is large, a lot of man-hours are required for manufacturing and assembling, which causes a problem such as an increase in cost.

The present invention has been made in order to improve the conventional problems, and an object thereof is to provide an optical pickup device which can be miniaturized.

[0022]

In order to achieve the above object, the present invention comprises an optical base to which an optical integrated device and an objective lens are fixed, a pressing spring for fixing the optical integrated device to the optical base, and an objective lens. An objective lens driving device that controls tracking in the focus direction and the tracking direction, and a steadying portion that suppresses vibration of the optical table, and a pressing spring,
It is characterized by integrally forming a steady rest that is pressed against the access shaft that guides the optical stand in the tracking direction, and there is no need to separately provide a steady spring that suppresses the optical stand from vibrating. Therefore, the optical pickup device can be downsized.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention has an optical system such as an optical integrated device and an objective lens, and an objective lens driving device for controlling the objective lens to follow the focus direction and the tracking direction. In the optical pickup device, a presser spring for fixing the optical integrated element to the optical table is provided with a steadying portion pressed against an access shaft for guiding the optical table in the tracking direction, and the presser spring is used as a steadying spring. It is also used for both purposes.

With the above construction, since it is not necessary to provide a steady rest spring for suppressing vibration of the optical table, the number of parts can be reduced and the optical pickup device can be downsized.

According to a second aspect of the present invention, the steady rest is formed so as to be substantially parallel to the access sub-axis when the presser spring is fixed to the optical bench, and the tip end portion thereof is in the access sub-axis direction. Since it is configured to be bent to absorb the vibration of the optical table, it is possible to prevent the tracking deviation from occurring due to impact or vibration.

A pressing spring according to a third aspect of the present invention is formed in a substantially L-shape, has an element mounting portion that projects obliquely from the vicinity of the bent portion of the pressing spring, and has a tip end portion of the element mounting portion. Is bent downward and an optical integrated device is attached to the tip.

Embodiments of the present invention will be described in detail below with reference to FIGS. 1 to 5. The same parts as those of the conventional optical pickup device will be described with the same reference numerals.

FIG. 1 is a plan view of the optical pickup device, and FIG.
4 is a front view thereof, FIG. 3 is a sectional view taken along line XX of FIG.
Is a plan view of the presser spring, and FIG. 5 is a side view of the same.

In these drawings, reference numeral 1 denotes an optical table, and both ends of the optical table are slidably hindered between an access main shaft 3 and an access auxiliary shaft 4 which are provided so as to be parallel to the tracking direction T of the optical disk 2. , An access direction A parallel to the tracking direction T by an access motor (not shown)
It can be moved to c.

An optical integrated device 5 and a reflection mirror 8 are installed at the end of the optical base 1 on the side of the access sub-axis 4 so as to be located below the access sub-axis 4.

The optical integrated device 5 is provided with a semiconductor laser that serves as a light source and a photoelectric conversion unit (both not shown) that photoelectrically converts the reflected light from the optical disk 2.
The integrated optical element 5 is fixed to the optical table 1 by a holding spring 6 which also functions as a steady spring.

As shown in FIGS. 4 and 5, the pressing spring 6 has a device spring 6a and a steady rest 6b formed of leaf springs.

The element mounting portion 6a is obliquely projected from the vicinity of the bent portion of the fixing portion 6c formed in a substantially L shape, and the tip portion is bent downward, and the optical integrated element 5 is mounted on the bent portion 6d. It is designed to be used.

The steady rest 6b is formed so as to be substantially parallel to the access auxiliary shaft 4 when the fixing portion 6c is fixed to the optical table 1 by the set screw 6e, and the tip side is bent obliquely upward. And the tip part is the accessory shaft 4 for access.
Is pressed from below.

On the other hand, in the central portion of the optical table 1, the laser light emitted from the semiconductor laser of the optical integrated device 5 is reflected toward the objective lens 9 side, and the laser light reflected from the optical disc 2 is integrated into the optical integrated device. The reflection mirror 10 that leads to the photoelectric conversion unit 5 is installed at an angle of 45 ° with respect to the optical axis of the objective lens 9.

An objective lens driving device 11 is installed above the reflection mirror 10.

The objective lens driving device 11 includes the optical table 1
It has a base 11a placed thereon, and a frame-shaped frame 11b is fixed to the base 11a.

A lens holder 9a to which an objective lens 9 is attached is provided at the center of the frame 11b.

One end of, for example, four metal wires 13 parallel to each other is fixed to the lens holder 9a.
The other end of 3 is fixed to the frame 11b, and the elasticity of the metal wire 13 holds the objective lens 9 movably in the vertical and horizontal directions.

A pair of magnet bodies 14 are attached to both ends of the lens holder 9a, and the frame 1
A focus coil 15 and a tracking coil 16 are provided on the 1b side so as to face the magnet bodies 14.

Next, the operation of the conventional optical pickup device having the above-mentioned structure will be described. When information is recorded on the optical disc 2, the laser light emitted from the semiconductor laser of the optical integrated device 5 is reflected by the reflecting mirror 10 and the objective. When the lens 9 collects and records as a small spot on the recording / reproducing surface of the optical disk 2 and reproduces the light, the reflected light from the optical disk is transferred to the photoelectric conversion unit of the optical integrated device 5 by the objective lens 9 and the reflecting mirror 10. Then, the signal is converted into an electric signal by the photoelectric conversion unit and reproduced.

If the optical disc 2 has a warp or an eccentricity, and a focus shift or a tracking shift occurs during recording or reproduction, the detection means (not shown) detects the shift and the focus coil 15 and the tracking so as to correct the shift. A control signal is applied to the coil 16.

As a result, the objective lens 9 is driven in the focus direction F and the tracking direction T, and the focus shift and the tracking shift are corrected.

On the other hand, while the optical table 1 is being moved in the tracking direction T by an access motor (not shown), even if a shock or vibration is applied, the steadying portion 6b of the pressing spring 6 is held.
Is pressed against the auxiliary shaft 4 for access from below, and the optical table 1
Since the vibration is absorbed, it is possible to prevent the tracking deviation from occurring due to impact or vibration.

[0045]

As described above in detail, according to the present invention, since the precession portion for fixing the optical integrated device to the optical base is provided with the precession preventing portion and also serves as the precession preventing spring, the conventional precession preventing spring is Becomes unnecessary.

As a result, the space for providing the spring may be small, so that the optical pickup device can be downsized and the number of parts can be reduced, so that the man-hours required for manufacturing and assembling can be reduced, and the optical pickup device can be reduced. The cost can be reduced.

[Brief description of drawings]

FIG. 1 is a plan view of an optical pickup device according to an embodiment of the present invention.

FIG. 2 is a front view of the optical pickup device according to the embodiment of the present invention.

3 is a cross-sectional view taken along line XX of FIG.

FIG. 4 is a plan view of a presser spring.

FIG. 5 is a side view of a presser spring.

FIG. 6 is a plan view of a conventional optical pickup device.

FIG. 7 is a front view of a conventional optical pickup device.

8 is a cross-sectional view taken along the line YY of FIG.

FIG. 9 is a side view of a steady rest spring.

[Explanation of symbols]

1 Optical stand 2 optical disc 3 Access spindle 4 Access sub-axis 5 Optical integrated device 6 Presser spring 6a Element mounting part 6b steady rest 6c Fixed part 6d bend 6e Set screw 7 steady spring 7a Set screw 8 reflection mirror 9 Objective lens 9a lens holder 10 reflective mirror 11 Objective lens drive 11a base 11b frame 13 metal wire 14 Magnet body 15 Focus coil 16 tracking coil

Claims (3)

(57) [Claims] 1. An optical base on which an optical integrated element and an objective lens are fixed, a pressing spring for fixing the optical integrated element to the optical base, and an objective lens drive for controlling the objective lens to follow the focus direction and the tracking direction. In an optical pickup device having a device and a steady rest for suppressing vibration of the optical stand, the pressing spring and the steady rest that is pressed against an access shaft for guiding the optical stand in the tracking direction are integrated. An optical pickup device characterized by being formed in a. 2. The steady rest is formed so as to be substantially parallel to the access sub-shaft when the pressing spring is fixed to the optical bench, and the tip end portion is bent in the access sub-axis direction. The optical pickup device according to claim 1, wherein the optical pickup device is provided. 3. The pressing spring is formed in a substantially L shape, and has an element mounting portion that projects obliquely from the vicinity of the bent portion of the pressing spring, and a tip end portion of the element mounting portion is bent downward. The optical pickup device according to claim 1, wherein the optical integrated device is attached to the tip portion.