JP3460136B2 - Optical information recording / reproducing 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 information recording / reproducing apparatus for irradiating an optical disk with a light beam condensed by an objective lens to record or reproduce information.

[0002]

2. Description of the Related Art FIG. 9 is an exploded perspective view showing the structure of an optical head portion of a conventional optical information recording / reproducing apparatus of this kind disclosed in, for example, Japanese Patent Laid-Open No. 20704/1993, and FIG. 10 shows its assembled state. 9 is a cross-sectional view taken along the line AA of FIG. 9, and FIG. 11 is an explanatory view showing a photodetector constituting the optical position detecting means in the direction of arrow D of FIG. In the figure, 1 is an objective lens, 2a and 2b are track control coils, 3 is a focus control coil, 4 is a triangular prism, and 5 is a track control coil 2a which is fixedly adhered to a lens holder 7 which constitutes a movable part. 2b and the relay substrate electrically connected to the focus control coil 3 by the lead wire 6, 8a and 8b are track control yokes which are fixedly adhered to the track control magnets 9a and 9b, and 10 is the focus control magnet 11a, This is a focus control yoke in which 11b is adhered and the support shaft 12 is press-fitted in the central portion. Further, 13 is a light emitting diode mounted on a base 15 which constitutes a fixed portion, and 14 is a two-divided photodetector for receiving the light flux emitted from the light emitting diode 13 via a triangular prism 4 attached to the back surface of the lens holder 7. And base 1
It is fixed at 5. The triangular prism 4 bends the light beam emitted from the light emitting diode 13 in a direction at a right angle and guides it to the two-part photodetector 14. The lens holder 7 has a bearing 7a formed in the center thereof, is fitted to the support shaft 12 and is supported so as to be slidable in the direction of arrow B and rotatable in the direction of arrow C, and the track control coils 2a and 2b. Is a track control yoke 8a, 8b and a track control magnet 9
The focus control coil 3 is arranged in a magnetic circuit composed of a and 9b, and the focus control coil 3 is arranged in a magnetic circuit composed of a focus control yoke 10 and focus control magnets 11a and 11b. Further, the lens holder 7 is attached to the base 15 by the support spring 16 and is elastically held so as to maintain the neutral position.

In such a structure, the lens holder 7 is moved in the direction of arrow B by passing a required current through the focus control coil 3 to control the focus of the objective lens 1. Further, the lens holder 7 is moved to the arrow C by applying a required current to the track control coils 2a and 2b.
And the track of the objective lens 1 is controlled.
The two-part photodetector 14 is arranged so that the parting line 14 a is parallel to the support shaft 12, as shown in FIGS. 9 and 11. Therefore, the light beam 17 from the light emitting diode 13 that is bent in the right angle direction by the triangular prism 4 and is incident on the two-divided photodetector 14 is accompanied by the movement of the lens holder 7 in the arrow C direction (track control direction). It moves on the light receiving surface of the two-divided photodetector 14 in the direction perpendicular to the dividing line 14a. Therefore, the rotation angle of the triangular prism 4 can be detected by taking the differential between the left and right photodetectors, and the amount of movement of the objective lens 1 in the arrow C direction can be detected.

[0004]

The conventional optical information recording / reproducing apparatus is constructed as described above, and the objective lens 1 and the track control coil 2 are provided in the lens holder 7 which is a movable part.
a, 2b, the focus control coil 3, the triangular prism 4, the relay substrate 5, and the like, it is necessary to mount many components, so that not only can the moving part be made smaller, lighter, and more rigid, but also the structure can be improved. However, there was a problem when it became complicated and assembly became difficult.

In view of the above points, the present invention can reduce the number of parts constituting the optical head, reduce the size and weight of the movable portion,
An object of the present invention is to obtain an optical information recording / reproducing device capable of achieving high rigidity.

[0006]

According to a first aspect of the present invention, there is provided an optical information recording / reproducing apparatus which holds an objective lens and a driving coil, and has an electric circuit means and a part thereof as a light reflecting means on the surface. It is equipped with an integrally formed lens holder, the light beam emitted from the light emitting means provided on the fixed base is reflected by the light reflecting means, and irradiates the photodetector provided on the fixed base. The position of the lens holder is detected based on the output signal of

In the optical information recording / reproducing apparatus according to the second aspect of the present invention, the light reflecting means and the electric circuit means of which the light reflecting means is a part have different inclinations, and the light emitting means is different. With respect to the light emitted from the device, only the reflected light from the light reflecting means is applied to the photodetector, and the reflected light from the electric circuit means is not applied to the photodetector.

[0008]

According to the first aspect of the present invention, the fixed base is provided with the objective lens and the driving coil, and the surface provided with the electric circuit means and the lens holder integrally formed with a part of the electric circuit means as the light reflecting means. The light beam emitted from the light emitting means provided in the is reflected by the light reflecting means, irradiates the photodetector provided on the fixed base, and the position of the lens holder is detected based on the output signal from the photodetector. Because I am
It is possible to eliminate parts such as relay boards and triangular prisms that were required in the past from the lens holder, and the number of parts is reduced, so that the moving part can be made smaller, lighter, and more rigid, and the The reflecting means can be used as a conducting path. Therefore, it is not necessary to form a circuit pattern that bypasses the light reflecting means, and the number of circuit patterns can be reduced accordingly, and the lens holder surface can be effectively used.

According to the second aspect of the present invention, the light reflecting means and the electric circuit means forming a part of the light reflecting means have different surface inclinations, and the light emitted from the light emitting means is Only the reflected light from the light reflecting means is applied to the photodetector, and the reflected light from the electric circuit means is prevented from being applied to the photodetector. Therefore, the light reflected by the electric circuit means other than the light reflecting means is prevented. It is possible to prevent the light from entering the photodetector.

[0010]

First, the background of the development of the present invention and the basic principle will be described before the description of the embodiments. FIG. 1 is an exploded perspective view showing a configuration of an optical head portion of an optical information recording / reproducing apparatus, FIG. 2 is a sectional view taken along the line EE of FIG.
Is a perspective view showing a state in which the movable part is assembled, and FIG.
FIG. 6 is a perspective view of the back side viewed from the arrow F direction in FIG.
The same reference numerals are attached to the portions corresponding to the conventional one (FIGS. 9 to 11). In the figure, 7A is a lens holder made of an insulating plastic, and the objective lens 1, the track control coils 2a and 2b, and the focus control coil 3 are bonded and fixed to form a movable part. On the front and back surfaces of the lens holder 7A, a circuit pattern 5A made of gold (Au) and a reflection pattern 4 made of gold (Au) are also formed by vapor deposition, etching or the like.
A and A are integrally formed. The track control coils 2a and 2b, the focus control coil 3, and the ends of the lead wires 6 are soldered to predetermined positions of the circuit pattern 5A for electrical connection. Further, 8a and 8b are track control yokes that are fixedly bonded to the track control magnets 9a and 9b, and 10 is a focus control yoke that has focus control magnets 11a and 11b that are bonded and a spindle 12 is press-fitted. Is a light emitting diode, 14
Is a two-divided photodetector that receives the light beam 17 emitted from the light emitting diode 13 and bent in the right angle direction by the reflection pattern 4A, and is fixed to the base 15 to form a fixed portion. A bearing 7a is formed in the center of the lens holder 7A, and the bearing 7a is fitted to the support shaft 12 so as to be slidable in the direction of arrow B and rotatable in the direction of arrow C, and the track control coils 2a and 2b are used for the track. The focus control coil 3 is arranged in the magnetic circuit including the control yokes 8a and 8b and the track control magnets 9a and 9b, and the focus control coil 3 includes the focus control yoke 10 and the focus control magnets 11a and 11b. It is placed inside. The lens holder 7A is attached to the base 15 by the support spring 16 and is elastically held so as to maintain the neutral position.

In such an optical information recording / reproducing apparatus, by passing a required current through the focus control coil 3, the lens holder 7A is moved in the direction of arrow B, and the focus control of the objective lens 1 is performed. Further, the lens holder 7A is moved in the direction of arrow C by passing a required current through the track control coils 2a and 2b, and the objective lens 1
Track control. Further, as shown in FIG. 1, the two-part photodetector 14 is arranged such that the parting line 14 a is parallel to the support shaft 12. Therefore, the light beam 17 from the light emitting diode 13 which is bent in the right angle direction by the reflection pattern 4A and is incident on the two-divided photodetector 14 is moved by the lens holder 7A in the arrow C direction (track control direction). It moves on the light receiving surface of the two-divided photodetector 14 in the direction perpendicular to the dividing line 14a. Therefore, by taking the differential between the left and right photodetectors, the rotation angle of the reflection pattern 4A can be detected, and the amount of movement of the objective lens 1 in the direction of arrow C can be detected. As described above, the circuit pattern 5A to which the focus control coil 3 and the track control coils 2a and 2b are connected and the reflection pattern 4A serving as the light reflection means are directly integrated on the front and back surfaces of the lens holder 7A which is a movable portion. By forming it, it is possible to eliminate components such as a relay substrate and a triangular prism, which have been conventionally required, from the lens holder 7A,
As the number of parts is reduced, the movable part can be made smaller, lighter and more rigid. Further, by forming the circuit pattern 5A and the reflection pattern 4A by vapor deposition, etching or the like, the patterns 5A and 4A can be formed in the same manufacturing process, and the manufacturing process of the lens holder 7A is simplified. However, even if the circuit pattern 5A and the reflection pattern 4A are directly formed on the front and back surfaces of the lens holder 7A as described above, if the circuit pattern 5A is formed so as to bypass the reflection pattern 4A, the circuit pattern 5A is formed. Cannot be reduced, and the lens holder surface cannot be effectively used. The present invention reduces the number of circuit patterns so that the lens holder surface can be effectively used.

Embodiment 1. FIG. 5 is a perspective view showing the structure of the movable part of the optical head part of the optical information recording / reproducing apparatus in the first embodiment of the present invention, and FIG. 6 is a perspective view of the back side viewed from the direction of arrow G in FIG. In each drawing, the same reference numerals are given to the portions corresponding to those in FIGS. 1 to 4 described above. The optical information recording / reproducing apparatus of this embodiment has a circuit pattern portion 5B formed on the upper surface of the lens holder 7B.
Part of the lens wraps around from the side surface of the lens holder 7B to the back surface,
A wide reflection pattern portion 4B is formed on the back surface side. Further, in the portion 5a of the circuit pattern 5B on the back surface other than the reflection pattern 4B, the inclination of the surface of the lens holder 7B is different from the inclination of the surface of the reflection pattern portion 4B, and the light is emitted from the light emitting diode 13 (see FIG. 2). The light reflected by the portion 5a other than the reflection pattern 4B is prevented from entering the two-divided photodetector 14.

As described above, in the optical information recording / reproducing apparatus of the present embodiment, a part of the circuit pattern portion 5B is set as the reflection pattern portion 4B, so that the reflection pattern portion 4 is formed.
B can be used as a conducting path. Therefore, it is not necessary to form a circuit pattern that bypasses the reflection pattern portion 4B, the number of circuit patterns can be reduced accordingly, and the surface of the lens holder 7B can be effectively used.

Example 2. FIG. 7 is a sectional view showing the structure of the movable part of the optical head part of the optical information recording / reproducing apparatus in the second embodiment of the present invention.
In the figure, parts corresponding to those in FIGS. 1 to 6 are given the same reference numerals. In the optical information recording / reproducing apparatus of this embodiment, the circuit pattern portion 5 on the surface of the lens holder 7C is used.
C is formed of copper (Cu), and only the reflection pattern portion 4C is formed of gold (Au) which is less likely to change with time such as rust.

In the optical information recording / reproducing apparatus of this embodiment, it is possible to freely select a material having good conductivity as the circuit pattern portion 5C and a material having high reflectance as the reflection pattern portion 4C. The degree of freedom in design is expanded.

Embodiment 3. FIG. 8 is a sectional view showing a structure of a movable portion of an optical head portion of an optical information recording / reproducing apparatus according to a third embodiment of the present invention,
In the figure, parts corresponding to those in FIGS. 1 to 7 are given the same reference numerals. In the optical information recording / reproducing apparatus of this embodiment, first, both the circuit pattern portion 5D and the reflection pattern portion 4D on the surface of the lens holder 7D are made of inexpensive copper (C).
u), and thereafter, only the surface of the reflection pattern portion 4D is covered with gold (Au) plating 4a which is less likely to change with time such as rust.

In the optical information recording / reproducing apparatus of this embodiment, both the circuit pattern portion 5D and the reflection pattern portion 4D are made of the same material copper (Cu), and only one surface of the reflection pattern portion 4D is formed. Since the expensive gold (Au) plating 4a is used for coating, even if an expensive material is used, it becomes a partial one, and the manufacturing cost can be prevented from increasing.

In this embodiment, the reflection pattern portion 4D
Although the case where gold (Au) is used as the material for covering the surface has been described as an example, instead of this, the surface of the reflection pattern portion 4D is coated with silver (Ag) plating having high reflectance, and this silver (Ag) is coated. The plated surface may be further coated with a rust preventive resin, in which case the manufacturing cost can be further suppressed.

By the way, in each of the above-described embodiments, the case where the two-divided photodetector is used as the light receiving element to detect the position of the objective lens in the track control direction (direction of arrow C in FIG. 1) has been described. In the same way, focus control direction (arrow B in Fig. 1)
It goes without saying that the position (direction) may be detected at the same time.

[0020]

As described above, according to the first aspect of the present invention, the objective lens and the driving coil are held, and the electric circuit means and a part thereof are integrally formed as the light reflecting means on the surface. The light flux emitted from the light emitting means provided on the fixed base is reflected by the light reflecting means,
The photodetector provided on the fixed base is irradiated, and the position of the lens holder is detected based on the output signal from this photodetector. The parts can be eliminated, the number of parts is reduced, and the movable part can be made smaller, lighter and more rigid, and the light reflecting means can be used as a conducting path. Therefore, it is not necessary to form a circuit pattern that bypasses the light reflection means, and the number of circuit patterns can be reduced accordingly.
The surface of the lens holder can be effectively used.

According to the invention of claim 2 of the present invention,
The light reflecting means and the surface of the electric circuit means of which the light reflecting means is a part have different inclinations, and the light emitted from the light emitting means is irradiated to the photodetector only by the reflected light from the light reflecting means,
Since the reflected light from the electric circuit means is not irradiated onto the photodetector, it is possible to prevent the light reflected by the electric circuit means other than the light reflecting means from entering the photodetector.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a configuration of an optical head portion of an optical information recording / reproducing apparatus for explaining a basic principle of the present invention.

FIG. 2 is a sectional view taken along the line EE in the assembled state of the one shown in FIG.

FIG. 3 is a perspective view showing an assembled state of the movable part of the one shown in FIG.

FIG. 4 is a perspective view of the back side viewed from the direction of arrow F in FIG.

FIG. 5 is a perspective view showing a configuration of a movable portion of an optical head portion of the optical information recording / reproducing apparatus according to the first embodiment of the present invention.

6 is a perspective view of the back surface side as seen from the direction of arrow G in FIG.

FIG. 7 is a sectional view showing a structure of a movable portion of an optical head portion of an optical information recording / reproducing apparatus according to a second embodiment of the present invention.

FIG. 8 is a sectional view showing a configuration of a movable portion of an optical head portion of an optical information recording / reproducing apparatus according to a third embodiment of the present invention.

FIG. 9 is an exploded perspective view showing a configuration of an optical head portion of a conventional optical information recording / reproducing apparatus.

10 is a cross-sectional view taken along the line AA in the assembled state of the one shown in FIG.

11 is an explanatory view showing a photodetector constituting the optical position detecting means of FIG. 9 from the direction of arrow D. FIG.

[Explanation of symbols]

1 Objective Lens, 2a, 2b Track Control Coil (Driving Coil), 3 Focus Control Coil (Driving Coil), 4A, 4B, 4C, 4D Reflection Pattern (Light Reflecting Means), 4a Gold Plating (Different Material) 5A, 5
B, 5C, 5D circuit pattern (electrical circuit means), 6 lead wires, 7A, 7B, 7C, 7D lens holder, 13
Light emitting diode (light emitting means), 14 two-part photodetector (photodetector), 15 base, 17 light beam.

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-6-96469 (JP, A) JP-A-2-185724 (JP, A) JP-A-6-176386 (JP, A) JP-A-5- 20704 (JP, A) JP 62-157334 (JP, A) JP 60-214431 (JP, A) Actual development 61-170121 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) G11B ^7/ 09-7/22

Claims (2)

(57) [Claims] 1. An optical information recording / reproducing apparatus for irradiating an optical disc with a light beam condensed by an objective lens to record / reproduce information, wherein the objective lens and a driving coil are held, and an electric circuit means is provided on the surface. A photodetector provided on the fixed base, which is provided with a lens holder, a part of which is integrally formed as light reflecting means, reflects the light flux emitted from the light emitting means provided on the fixed base by the light reflecting means. And an optical information recording / reproducing apparatus configured to detect the position of the lens holder based on an output signal from the photodetector. 2. The light reflecting means and a part of the light reflecting means
The inclination of the surface of the electric circuit means is different,
The light emitted from the means is reflected light from the light reflecting means.
Only the photodetector is illuminated and the reflected light from the electrical circuit means
The optical information recording / reproducing apparatus according to claim 1, wherein the photodetector is not irradiated .