JP2703602B2 - Galvano mirror support device for pickup device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a galvanomirror support device for a pickup device.

[Conventional technology]

As shown in FIG. 6A, the focus (in the z-axis direction) of the optical pickup device is formed by attaching a pipe-flange-shaped magnetic piece 30c to a lower surface of a magnetic piece 30b on the upper surface of a ring-shaped permanent magnet 30a, and forming the gap between the two magnetic pieces. The objective lens driving voice coil 30d in which the objective lens 31 is mounted is provided in the space thus formed, and the current flowing through the coil 30d moves the objective lens driving voice coil 30d up and down (z-axis direction) based on Fleming's left-hand rule. This is done by a so-called voice coil electromagnetic drive 30 that moves to

In the tracking (x-axis direction) control, permanent magnets 32a are attached to both ends in the x-axis direction on the back surface of the galvanometer mirror 32, and an elastic body 32b that supports a central portion of the galvanometer mirror 32 at one point is provided.
Is fixed to the base 32c at an angle with respect to the x-axis, and the coil 32d surrounding the galvanomirror 32 is fixed to the base 32c, and the galvanomirror 32 is rotated in the direction of the arrow by the current flowing through the coil 32d. Let go. Reference numeral 33 denotes a semiconductor laser, and reference numeral 34 denotes a disk information surface on which information is recorded.

FIG. 6B shows the operation of the optical system in the optical pickup device. The light beam emitted from the semiconductor laser 33 is converted into a parallel beam by the collimator lens 35, and the polarization beam splitter 36 and the quarter-wave plate 37 are used. Through galvanomirror 3
The light is deflected by 90 ° at 2 and passes through the objective lens 31 to the disc information surface 3
4 converges, reflected light is objective lens 31, galvanometer mirror 3
Returning to the 2/4 wavelength plate 37, the light beam is deflected by 90 ° by the polarizing beam splitter 36, passes through the light shielding plate 38,
, And a focus error signal, a tracking error signal, and an information signal are obtained.

By the way, the optical pickup device is required to be reduced in size and weight. One of the solutions is to make the optical pickup device thin by shortening the length in the z-axis direction. However, the galvanomirror 32 is supported at one point by an elastic body 32b projecting perpendicularly from the base portion 32c to the surface of the base portion 32c at a certain angle with respect to the x-axis, and the coil 32d surrounds the galvanomirror 32 by a coil. Since the galvanomirror 32 is rotatably supported in a tilted state by being fixed to the portion 32c, the height H of the coil 32d has been an obstacle in reducing the thickness.

As means for solving this, for example, there is one disclosed in Japanese Patent Application Laid-Open No. 58-88837. As shown in FIG. 7, a plate-like elastic body 42 is attached to the back surface of the galvanomirror 41, and the winding directions of the galvanomirror 41 on both sides perpendicular to the plate-like elastic body 42 are equal to those of the galvanomirrors 41 and 45 °. One side of the inclined hollow rectangular coil 43 is vertically symmetrically mounted around the plate-like elastic body 42, and a hollow magnet 44 composed of a permanent magnet piece and a magnetic piece is provided in the hollow portion of the rectangular coil 43 and a magnet is picked up. A shaft 42a fixed to the base and projecting from the plate-like elastic body 42 on both sides in the longitudinal direction is mounted on a pickup base outside the rectangular coil 43.

[Problems to be solved by the invention]

However, in the above-mentioned prior art, since the rectangular coil magnetic circuit is provided so as to surround the plate-like elastic body, there are disadvantages that the number of parts is increased, the cost is increased, and it is not easy to assemble the pickup device, and the production efficiency is poor.

SUMMARY OF THE INVENTION The present invention has been proposed to solve the above problems, and has as its object to provide a galvanomirror support device for an optical pickup which is thin and easy to assemble.

[Means and actions for solving the problem]

In order to achieve the above object, the present invention provides a pair of magnetic field means on both the left and right sides, a reflecting means having a light reflecting surface inclined at a required angle with respect to the magnetic flux direction at the center of the magnetic field means, and A pair of driving means for generating a driving force in cooperation with the magnetic field means is provided so as to move integrally, and the reflecting means and the driving means are connected to the pickup device fixing member on both sides of the driving means in the arrangement direction. It is supported so as to be able to be driven through.

As described above, the pair of magnetic field units are each configured with the minimum number of components, and the reflection unit and the driving unit are supported so as to be integrally movable via the support unit provided on the side of the driving unit, so that the number of components is the minimum. In addition, a thin galvanomirror support device can be obtained.

〔Example〕

FIG. 1 is an exploded perspective view showing a first embodiment of the present invention. Mirror receiving portion 1a having an inclined bottom, this mirror receiving portion 1a
The holder 1 having no bottom is formed integrally on both sides of the holder 1 with, for example, plastic. The mirror 2 is fixed to the mirror receiving portion 1a, and the reflection surface 2a is inclined by approximately 45 ° with respect to the direction of the magnetic flux generated by the coil 3 described later. Both coil receiver
The coil 3 wound in a prismatic shape is fixed at a required position 1b.

Reference numeral 4 denotes a base made of a magnetic material such as iron, and a recess 4a in which the lower portion of the mirror receiving portion 1a of the holder 1 is located is formed at the center. Magnets are provided on both sides of the recess 4a in the longitudinal direction of the base 4. A mounting projection 4b is provided. A pair of yokes 4c are provided on both sides of the base 4 in the width direction of the bases 4b, and a magnetic gap is formed between the yoke 4c and the magnetic pole surface of the magnet 5 mounted and fixed on the base 4b.

Holder 1 to which mirror 2 and coil 3 are fixed as described above
Is provided on the base 4, the lower portion of the mirror receiving portion 1 a is located in the concave portion 4 a and the magnet 5 is
It is performed so that it is located in. In this case, the operation is performed via an assembling jig with reference to the reflecting surface 2a so that the reflecting surface 2a of the mirror 2 is at a required position. Reference numeral 4d denotes a concave portion for making the light beam approach the base when the light beam incident on the mirror 2 passes on the base 4.

Spring receiving portions 6 having pins 6a are formed on both outer sides in the longitudinal direction of the coil receiving portions 1b of the holder 1 passing through the mirror receiving portions 1a. In the vicinity of the center of both ends in the longitudinal direction of the base 4, a spring receiving base 7 having a pin 7a is provided. The holder 1 is provided on the base 4 as described above.
And a spring 8 is hooked over a spring support 7 on the base 4 and fixed. The spring 8 is formed by etching or pressing a metal such as beryllium copper having a thickness of about 0.1 mm, has a narrow central portion, has holes 8b at both ends, and has a portion around the narrow portion at the central portion. A damping member 8a such as butyl rubber is provided. hole
8b is on the pin 6a of the holder 1 and the other is on the spring support 7
After engaging with the pin 7a and positioning it, the holder 1 having the mirror 2 and the coil 3 is drivable.

FIG. 2 is a perspective view of an assembled state. In order to supply power to the coil 3 for driving the holder 1, the coil end may be wired along the spring 8, or the spring 8 may be insulated from the base 4 and the spring 8 may be used as a power supply member. The magnetic circuit may have a configuration in which a pair of magnets having an outer yoke are provided with an inner yoke having a coil disposed on the outer periphery thereof interposed therebetween. Also in this configuration, the number of coils is small and the number of parts is reduced, and the magnetic circuit and the support spring do not interfere with each other in space, and thus the assembly is easy.

 FIG. 3 is a central longitudinal sectional view in the width direction in an assembled state.

With this configuration, the present embodiment will be described with reference to FIG.
As shown in FIG. 2A, when an electric current is applied to the coil 3, the coil 3 is positioned in the magnetic gap formed by the magnet 5 and the yoke 4c in parallel with the y-axis direction. Mutually opposing forces occur. Then, the holder 1 that is drivably supported on the base 4 via the spring 8 is
Is twisted and the whole tilts. Therefore, the reflecting surface 2a of the mirror 2 is tilted so that the optical path reflecting the reflecting surface 2a can be tilted to perform tracking control.

In this embodiment, since the mirror 2 is easily tilted by the coil 3, the magnetic circuit, and the spring 8, a thin galvanomirror support device having a small number of components and high production efficiency can be obtained. In addition, particularly in assembling, since the mirror 2 is performed with respect to the base 4 with reference to the reflection surface of the mirror 2, the holder 1 is supported via a spring 8. , Position accuracy can be realized.

FIG. 5 shows a second embodiment of the present invention. In this embodiment, a galvanomirror supporting device 10 is provided below a base 9 and an objective lens driving device 11 is provided above the base. The configuration of the galvanometer mirror support device 10 is almost the same as that of the first embodiment, and the mirror 12 is fixed to the holder 13,
A coil 15 is disposed in a magnetic gap formed by a magnet 14 and a yoke, and a mirror 12 and a holder 13 having the coil 15 are provided.
Are drivably attached via a spring 16 to a spring receiving portion 17 protruding from the base 9. 17a and 18 are pins formed on the spring 16 when the spring 16 is fixed and engaged with the holes. When an electric current is applied to the coil 15, forces opposite to each other in the z-axis direction are generated in the coils 3 on both sides of the mirror 12, and the spring 16 is twisted and the holder 3 is twisted.
13 is tilted, the reflecting surface 12a of the mirror 12 is tilted, and the optical path reflecting the reflecting surface 12a is tilted to perform tracking control.

On the other hand, in the objective lens driving device 11, the objective lens
Reference numeral 19 is fixed to a holder 20, and a focus coil 21 is wound around the holder 20. Although two strip-shaped focus springs 22 are shown, two more are provided so as to correspond to each other, and the holder 20 is movably supported by a total of four focus springs 22. One end of the focus spring 22 is fixed to the holder 20 and the other end is fixed to the holding member 23.
On the base 9, a pair of outer yokes 24 and a pair of inner yokes 25
A holding member 23 is fixed to one of the outer yokes 24, and a magnet 26 is provided inside each of the outer yokes 24.
Is fixed.

With this configuration, when a current flows through the focus coil 21, a force in the focus direction (z-axis direction) is generated in cooperation with the magnetic field generated by the magnet 26, and the focus spring 22 is deformed in the focus direction. The objective lens 19 can be moved in the focus direction. The light beam emitted from the light source in this way is reflected while being track-controlled and is incident on the objective lens 19, and is also subjected to focus control to irradiate a spot on the recording medium surface.

〔The invention's effect〕

As described above, according to the present invention, the number of coils and magnets used in the galvanomirror support device is minimized, so that the production efficiency is good and the cost can be reduced. Further, since the mirror supporting member is located on the side of the coil, a thin device having a small height can be obtained.

When the base of the pickup device is shared with the drive device of another optical system, the height of the entire device can be further reduced and the number of components can be reduced. Also,
High-speed access and the like are made possible by reducing the weight.

[Brief description of the drawings]

 FIG. 1 is an exploded perspective view showing a first embodiment of the present invention, FIG. 2 is an assembling drawing, FIG. 3 is a longitudinal vertical sectional view in the same width direction, and FIG. Fig. 5 is a side view showing a second embodiment of the present invention, Figs. 6A and 6B are schematic views showing a conventional example, and Fig. 7 is a perspective view of a main part showing another conventional example. 2 ... Mirror, 3 ... Coil 4 ... Base, 4c ... Yoke 5 ... Magnet, 8 ... Spring

Claims (2)

(57) [Claims] 1. A pair of magnetic field means are provided on both left and right sides, and a reflecting means having a light reflecting surface inclined at a required angle with respect to a magnetic flux direction is provided at the center of the magnetic field means, and the reflecting means cooperates with the magnetic field means. A pair of driving means for generating a driving force is provided so as to move integrally, and the reflecting means and the driving means can be driven on both sides of the driving means in the arrangement direction to the pickup device fixing member via a supporting member. A galvanomirror support device for a pickup device, wherein the device is supported. 2. A galvanomirror for a pickup device, wherein a reflecting means and a driving means which move together are supported by a pickup member fixing member for fixing a driving device of another optical system via a supporting member. Support device.