JP2002123958A - Optical disk recording/reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compact, high-speed and large-capacity optical disk recording/reproducing device. SOLUTION: This device is provided with a heat radiator 3 installed in the position of the rotary shaft of a swing arm, an LD(laser diode) 2 attached to the heat radiator 3, a collimator lens 1 for making parallel lights emitted from the LD 2, an objective lens 6 attached to the tip of an arm for radiating parallel laser beams, and a detection system disposed near the objective lens 6 to generate focusing and tracking signals. Thus, a focus setting range is secured even if the lens has a small diameter/high NA, and heat is radiated from the LD 2. Also, focusing and tracking signal detection systems corresponding to the heat radiation of the LD 2 of the swing arm system and the objective lens 6 of small diameter/high NA are simultaneously disposed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk recording / reproducing apparatus, and more particularly, to an optical disk recording / reproducing apparatus which radiates heat of an LD (laser diode) with high efficiency.

[0002]

2. Description of the Related Art Conventionally, an optical disk recording / reproducing apparatus is generally provided with a radiator. As a heat radiation method, there are a heat radiation method of an LD in a swing arm method and a linear motor slider method.

[0003]

However, in the above-mentioned conventional general slide method, an LD is assembled to a pickup together with a radiator. In the slide method using a linear motor, there is a method of arranging an LD and a detection system outside and irradiating an optical system on a slider (JP-A-63-224).
037).

In the swing arm system, when the objective lens is large (several millimeters), the heat of the LD can be radiated by irradiating a laser beam to the center of the arm (JP-A-11-195233) or by disposing the LD at the center of the arm. Can be secured (Japanese Patent Laid-Open No. 5-14407)
2).

In a general slide method, there is a method of arranging an LD and a detection system outside and irradiating an optical system on a slider with a slide method using a linear motor assembled with a pickup and a heat radiator. . In the swing arm system, when the objective lens is large (several millimeters), heat radiation of the LD can be ensured by irradiating a laser beam to the center of the arm or disposing the detection system and the LD at the center of the arm.

In the slide system and the swing arm system using a linear motor, the objective lens has a small diameter (1).
In the case of (millimeters or less) and a high NA (> 7), the position where the focus and track signal detection system can be arranged becomes a short distance. Therefore, there is no detection system near the end of the slider or near the arm rotation axis.

When the lens diameter becomes 1 / n, the position showing the same focus sensitivity becomes shorter than L / n when the distance between the objective lens and the detection system is L (L / n is required to make the focus pull-in range the same). n2). Also, as the NA increases, the fluctuation due to defocus increases, so that it must be further shortened. Placing an optical pickup including an LD on the end of an arm or on a linear motor becomes heavy in view of a heat radiator, which impairs high-speed operation.

The present invention provides a small-sized, high-speed, large-capacity optical disk recording / reproducing apparatus which configures an optical system so that a load is not relatively applied to a voice coil or a linear motor, enables use of a small-diameter, high-NA objective lens. To make it feasible.

It is an object of the present invention to achieve both the heat radiation of a swing arm type LD and the arrangement of a focus and track signal detection system corresponding to an objective lens having a small diameter and a high NA.

A second object of the present invention is to realize a case where the distance cannot be obtained due to the quality of the collimated light of the LD and to make the detection system and the LD an optical system integrated with each other to facilitate the adjustment.

[0011] Claims 3 and 5 aim at increasing the heat capacity in claim 1.

Claims 4 and 6 aim at increasing the heat capacity in claim 2.

A seventh object of the present invention is to improve the heat radiation speed in the second embodiment.

An eighth object of the present invention is to improve the heat radiation speed in the sixth embodiment. It is an object of the present invention to achieve both the heat radiation of the linear motor type LD and the arrangement of the focus and track signal detection system corresponding to the small-diameter and high-NA objective lens.

[0015]

In order to achieve the above object, an optical disk recording / reproducing apparatus according to claim 1 is a swing arm type optical disk recording / reproducing apparatus, wherein a radiator provided at a position of a rotation axis of the swing arm is provided. An LD (laser diode) attached to the heat radiator, a collimator lens that collimates the light emitted by the LD, an objective lens attached to the tip of an arm that irradiates the collimated laser beam, And a detection system arranged near the lens to generate focus and tracking signals.

According to a second aspect of the present invention, there is provided a swing arm type optical disk recording / reproducing apparatus, wherein a heat radiator is provided at a position of a rotation axis of the swing arm, and a high-speed heat conductor (for example, a heat pipe) is provided along the arm. A laser diode (LD) is attached to the high-speed heat conductor, and a detection system that generates focus and tracking signals integrated with the LD is placed. It is characterized by having been constituted so that.

According to a third aspect of the present invention, in the optical disk recording / reproducing apparatus according to the first aspect, the counterbalance is also a radiator.

According to a fourth aspect of the present invention, in the optical disk recording / reproducing apparatus according to the second aspect, the counterbalance is also a radiator.

According to a fifth aspect of the present invention, in the optical disk recording / reproducing apparatus according to the first aspect, a larger heat radiator is provided via a rotating shaft of a high-speed heat conductor in contact with the heat radiator.

According to a sixth aspect of the present invention, in the swing arm type optical disk recording / reproducing apparatus, the rotating shaft of the swing arm is a high-speed heat conductor 1 (for example, a heat pipe).
The high-speed heat conductor 2 is arranged along the arm, and the high-speed heat conductor 2 is brought into contact with the high-speed heat conductor 1. An LD (laser diode) is attached to the high-speed heat conductor 2.
And a detection system that generates a focus and tracking signal integrated with the LD is arranged, and a parallel laser beam is irradiated to the objective lens at the tip of the arm.

According to a seventh aspect of the present invention, in the optical disk recording / reproducing apparatus according to the second aspect, a radiation fin is provided on the high-speed heat conductor.

According to an eighth aspect of the present invention, in the optical disk recording / reproducing apparatus according to the sixth aspect, a radiation fin is provided on the high-speed heat conductor.

According to a ninth aspect of the present invention, there is provided an optical disk recording / reproducing apparatus having a slide type seek mechanism using a linear motor, wherein a laser beam is irradiated in a sliding direction toward an optical pickup on the linear motor.
D can be fixed to the end together with the heat radiator.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of an optical disk recording / reproducing apparatus according to the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 to FIG. 8 show an embodiment of an optical disk recording / reproducing apparatus according to the present invention.

Embodiment 1 FIG. 1 shows a swing arm using a general voice coil motor. FIG. 2 shows a configuration example. The heat radiator 3 is arranged around the rotation axis (including the upper part), and the LD 2 is attached. The collimator lens 1 is arranged on the front surface of the LD 2 and radiates parallel light to the optical system at the tip of the arm.

FIG. 3 shows details of the optical system at the tip of the arm.
Parallel light from LD2 is reflected by mirror 4 or deflection prism
The objective lens 6 is irradiated through the 1 / 4λ plate 5 bent at 90 degrees to form a spot on the disk surface. The laser beam reflected from the disk 7 is applied to the objective lens 6 1/4 λ plate 5 mirror 4
, The light reflected at 90 degrees on the half mirror surface of the optical path separating prism (PBS) 8 is condensed by the detection lens and
At D, focus error and track error (focus and track signal) are detected. In this way, even if the lens has a small diameter and a high NA, the focus pull-in range can be secured, and the heat radiation of the LD 2 can be performed.

The load on the voice coil motor for driving the swing arm does not increase so much, and the seek (track positioning) speed does not need to be reduced. Here, the light separated by the PBS 8 is detected by the PD, but the present invention does not specify the detection method only as a typical example.

(Embodiment 2) FIG. 4 shows a configuration example. An LD is installed via a high-speed heat conductor (such as a heat pipe) 10 from a heat radiator disposed around the rotation axis, and the objective lens / mirror unit and the focus and track signal detection unit 9 in FIG. 3 are separated. (The position where the focus pull-in range can be secured).

If the detection unit 9 is a unit in which the LD is integrated, the optical axis and the like can be adjusted by the unit, and only the direction adjustment is performed on the arm, and the efficiency of assembly and adjustment is increased. Also,
If the quality of the parallel light generated by the LD and the collimating lens is poor, the light gradually spreads. Since the distance between the LD and the objective lens can be shortened, there is no problem even if the quality of the parallel light is somewhat poor. Although the objective lens unit 6 and the detection unit 9 are separated in FIG. 4, if there is no problem in weight, it is also possible to mount the objective lens unit 6, the detection unit 9 and the LD as an integrated unit at the end of the arm. .

(Embodiment 3) In the case where the heat capacity of the heat radiator is insufficient in the embodiment 1 and the embodiment 2, the swing arm is generally provided with a counter weight on the voice coil side in order to balance the rotation moment. is there. In this case, as shown in FIG. 5, the heat capacity is increased by using a heat radiator including a counterway.

Fourth Embodiment In the second embodiment, if the total weight on the arm has a margin, a plurality of radiation fins as shown in FIG. Thus, adverse effects on the LD due to temperature can be reduced, and more stable recording can be performed.

(Embodiment 5) In order to improve the recording speed, an LD having a higher output is used. If the third embodiment is still insufficient, as shown in FIG. 7, the rotating shaft 21 is a high-speed radiator, and a further radiator provided on the base portion in contact with the radiator or a frame or the like is made of aluminum or the like. Then, the rotating shaft 21 may be directly installed on the frame. If the frictional resistance between the heat radiator and the rotating shaft 21 becomes large, a load is applied to the voice coil motor. Therefore, in FIG. 7, a high-speed heat conductor such as a heat pipe sphere is used as a bearing instead of the heat radiator itself as a bearing. What should I do? In the case of the heat pipe 10 as in (Embodiment 2), if the rotating shaft is sandwiched between the two heat pipes, heat can be sufficiently radiated by the radiator or frame on the base.

(Embodiment 6) FIG. 8 shows a configuration example. In the case where a slider type seek mechanism using a linear motor is provided, the optical pickup as in the first embodiment) is irradiated with parallel light generated by an externally mounted LD and a collimating lens.

[0034]

As is apparent from the above description, in the optical disk recording / reproducing apparatus according to the first aspect, the heat radiator is provided around the swing arm type rotating shaft. For this reason,
The balance of the rotational moment is not lost, and the load on the voice coil motor does not increase so much. As a result, the high-speed operation can be maintained, and the detection system can be arranged at a position corresponding to the small-diameter, high-NA objective lens.

In the apparatus according to the second aspect, the heat can be conducted to the radiator around the rotating shaft by the lightweight high-speed heat conductor. For this reason, since the LD can be disposed integrally with the detection system, it is possible to cope with the case where the collimation quality of the LD is poor (spread little by little) in addition to the case of the first aspect. Further, by forming the detection system and the LD as a unit, the efficiency of assembly and adjustment is improved.

In the device of the third aspect, in addition to the effect of the first aspect, since the heat capacity of the heat radiator increases, it is possible to cope with writing with a higher output LD power.

In the device of the fourth aspect, in addition to the effect of the second aspect, since the heat capacity of the radiator increases, it is possible to cope with writing with a higher output LD power.

In the device according to the fifth aspect, since the heat capacity of the radiator is further increased as compared with the third aspect, it is possible to cope with writing with a higher output LD power.

According to the device of the sixth aspect, in addition to the effect of the fourth aspect, the heat capacity of the radiator is increased, so that it is possible to cope with writing with a higher output LD power.

In the device according to the seventh aspect, in addition to the effect of the second aspect, since the heat radiation speed is also improved, the output of the LD is more stabilized.

In the device of the eighth aspect, in addition to the effect of the sixth aspect, the heat radiation speed is improved, so that the output of the LD is more stabilized.

In the apparatus according to the ninth aspect, since only the objective lens, the mirror, and the detection system are mounted on the slider portion of the slider type linear motor, the weight of the mirror and the detection system increases, but the small diameter and high NA Therefore, considering that the focus actuator can be made smaller, the weight becomes lighter, so that a small and large capacity capable of high-speed operation can be realized.

[Brief description of the drawings]

FIG. 1 shows a swing arm using a general voice coil motor, showing an embodiment of an optical disk recording / reproducing apparatus of the present invention.

FIG. 2 shows a more detailed configuration example of the voice coil motor of FIG.

FIG. 3 is a diagram illustrating a detailed configuration example of an optical system at an end of an arm.

FIG. 4 is a diagram showing a configuration example in which an LD is installed from a heat radiator arranged around a rotation axis via a high-speed heat conductor (such as a heat pipe).

FIG. 5 is a diagram illustrating a configuration example when a heat capacity of a heat radiator is increased.

FIG. 6 is a diagram showing a configuration example in the case where a radiator fin is provided.

FIG. 7 is a diagram showing a configuration example in a case where a rotating shaft is provided as a high-speed radiator and provided on a base portion in contact with the radiator.

FIG. 8 is a diagram showing a configuration example in a case where parallel light generated by an LD and a collimator lens attached to the outside is irradiated.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 collimating lens 2 LD 3 radiator 4 mirror 5 (bend 90 degrees) 1 / 4λ plate 6 objective lens 7 disk 8 optical path separating prism (PBS) 9 detector 10 heat pipe 21 rotation axis

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01S 5/022 H01S 5/022 5/024 5/024

Claims (9)

[Claims] 1. A swing arm type optical disk recording / reproducing apparatus, comprising: a heat radiator provided at a position of a rotation axis of a swing arm; an LD (laser diode) attached to the heat radiator; A collimating lens, an objective lens attached to the tip of the arm that irradiates the parallel laser beam, and a detection system arranged near the objective lens to generate focus and tracking signals. Optical disk recording and reproducing apparatus. 2. A swing arm type optical disk recording / reproducing apparatus, wherein a heat radiator is provided at a position of a rotation axis of the swing arm, and a high-speed heat conductor (for example, a heat pipe) is provided along the arm.
And a LD (laser diode) attached to the high-speed heat conductor, and a detection system that generates focus and tracking signals integrated with the LD is placed. The parallel laser beam is applied to the objective lens at the tip of the arm. An optical disc recording / reproducing device, characterized in that the device is configured to irradiate. 3. The optical disc recording / reproducing apparatus according to claim 1, wherein the counter balance is also a heat radiator. 4. The optical disk recording / reproducing apparatus according to claim 2, wherein the counter balance is also a heat radiator. 5. The optical disk recording / reproducing apparatus according to claim 1, wherein a larger heat radiator is provided via a rotating shaft of a high-speed heat conductor in contact with the heat radiator. 6. A swing arm type optical disk recording / reproducing apparatus, wherein a high-speed heat conductor 1 (for example, a heat pipe) is used as a rotation axis of the swing arm, and a high-speed heat conductor 2 is arranged along the swing arm. The heat conductor 2 is brought into contact with the high-speed heat conductor 1, an LD (laser diode) is attached to the high-speed heat conductor 2, and detection for generating a focus and tracking signal integrated with the LD An optical disc recording / reproducing apparatus, comprising: a system for irradiating an objective lens at an end of an arm with a parallel laser beam. 7. The optical disk recording / reproducing apparatus according to claim 2, wherein a radiation fin is provided on the high-speed heat conductor. 8. The optical disk recording / reproducing apparatus according to claim 6, wherein a radiation fin is provided on the high-speed heat conductor. 9. An optical disk recording / reproducing apparatus having a slide type seek mechanism using a linear motor, wherein a laser beam is irradiated in a sliding direction toward an optical pickup on the linear motor, and the LD is radiated to an end. An optical disc recording / reproducing device, characterized in that it can be fixed together with the body.