JPS6313137A - Optical information recording and reproducing device - Google Patents

Abstract

PURPOSE:To prevent lateral vibration due to resonance by allowing a support means to support both side ends of a holding member and allowing a moving torque giving means to give a moving torque to a part corresponding to a node of the primary lateral vibration of a moving optical system. CONSTITUTION:A support means supporting a pickup body 7 freely movable by both support railes 5, 6 steel-made rollers 8, 9, a spring member 13 and peripheral small members relating to them along the recording face of a disk 15 is constituted. A couple of magnetic circuits 20 comprising a long magnet 16 and long yokes 17, 18 prolonged respectively in the moving direction being the Y direction of the body 7 and its opposite direction and engaged with each other is fixed to a frame 1. Further, a couple of drive coils 21 are fitted to the body 7 so that the coil center axis is in parallel with the moving direction of the body 7 and the magnetic circuit 20 generates the magnetic flux interlinked with the drive coil 21 to constitute a linear motor. The linear motor gives a moving torque to a part corresponding to the mode of the primary lateral vibration of the moving optical system including the body 7.

Description

[Detailed description of the invention] Technical field The present invention relates to an optical information recording/reproducing device.

BACKGROUND ART Information recording media such as video discs and digital audio discs are recorded by irradiating the recording surface with a minute spot light to form pits in a spiral track according to the information signal. It records information signals. Further, when reproducing an information signal recorded in this manner, a spot light is irradiated onto the track and the reflected light or transmitted light is used to reproduce the original information signal.

Various devices for reproducing or recording information signals have already been developed. Specifically, the device includes, for example, a light emitting element such as a laser diode, an objective lens that focuses the irradiation light emitted by the light emitting element on the disk recording surface as a spot light, and a device that precisely directs the irradiation light to a predetermined position on the disk recording surface. It includes a servo drive mechanism that servo drives the objective lens in the direction of the optical axis of the objective lens and in a direction perpendicular thereto to achieve focusing. Of these, at least the objective lens and the servo drive mechanism are held by a predetermined holding member, and are moved together with the holding member along the disk recording surface as the disk rotates. Therefore, a support means for movably supporting the holding member along the disk recording surface and a moving force applying means for applying a moving force to the holding member are provided. As shown in FIG. 10, the support means usually consists of a pair of support rails 101 extending along the disk recording surface, and longitudinal holding members 102 holding the objective lens etc. are attached at both ends thereof. It is slidably attached to both support rails.

In the optical information recording/reproducing apparatus having such a configuration, the frequency of the moving force applied by the moving force applying means and the natural frequency (- If the following conditions match, as shown in FIG. 10, there is an inconvenience that the moving optical system causes transverse vibration due to resonance.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned points, and its object is to provide an optical information recording/reproducing apparatus in which a moving optical system does not cause lateral vibration.

The optical information recording and reproducing device according to the present invention includes an objective lens,
A moving optical system including a servo drive mechanism and a longitudinal holding member that holds these; supporting means that supports both ends of the holding member and guides it along the recording surface of a recording medium; and a moving optical system that applies a moving force to the moving optical system. and a moving force applying means that applies a moving force to a portion of the moving optical system corresponding to a node of primary transverse vibration.

Embodiments Hereinafter, optical information recording and reproducing apparatuses as embodiments of the present invention will be described with reference to the accompanying drawings.

A frame 1 shown in FIGS. 1 to 4 is provided within a housing (not shown) of the optical information recording/reproducing apparatus, and has four leg members 2.3 with respect to the housing.
It is attached via. Note that the frame 1 is made of aluminum or an alloy thereof.

A pair of cylindrical steel support rails 5 and 6 extending in the direction of arrow Y and the opposite direction and spaced apart in the direction of arrow Z and the opposite direction are fixed to this frame 1 at both ends thereof. .

A longitudinal pickup body 7 as a holding member extending in the arrow Z direction and the opposite direction is attached to both support rails 5.
, 6, and is movably supported by both support rails. This pickup body 7 is also made of aluminum or its alloy. Two steel rollers 8 are attached to one side of the pickup body 7 to roll on the support rail 5.

There are also two on the other side of the pickup body 7, a total of 4
Two other steel rollers 9 are mounted at two intervals apart in the direction of movement of the pickup body, and are in contact with the other support rail 6. As is particularly clear from FIG. 4, the pickup body 7 is supported at three points by both support rails 5 and 6 via the aforementioned rollers 8 and 9.

As shown in FIG. 4, a roller 8 provided on one side of the pickup body 7 moves the bin 1 to the pickup body.
1 to the free end of a swing lever 12 which is swingably mounted in the direction of arrow R. Note that the direction of arrow R is perpendicular to the direction of movement of the pickup body (the direction of arrow R and the opposite direction). Further, a spring member 13 is provided as a pressing means for pressing the roller 8 against the support rail 5. 3 mentioned above
By pressing the roller 8 on the one point side of the point support against the support rail 5 in this way, the rollers 9 on the other two point sides are also pressed against the other support rail 6 by the reaction force. Note that the optical information recording/reproducing device is installed so that the direction of arrow Z is the anti-gravitational direction. That is, the roller 8 on the one-point side is always positioned in the anti-gravity direction with respect to the roller 9 on the two-point side. Thereby, the spring member 13 for pressing the roller 8 against the support rail 5 is not subjected to a large weight such as the pickup body diff.

In addition, both the above-mentioned support rails 5.6 and the steel rollers 8,
9, the spring member 13, and peripheral small members related thereto constitute a support means that supports the pickup body 7 so as to be movable along the recording surface of the disk 15, which is a recording medium.

As shown in FIGS. 2 and 4, in frame 1,
A pair of longitudinal magnetic circuits 20 are fixed, each extending along the direction of movement of the pickup body 7 (the direction of arrow Y and the opposite direction thereof) and consisting of a longitudinal magnet 16 and a longitudinal yoke 17, 18 which are engaged with each other. Further, as shown in FIG. 2, a pair of drive coils 21 are attached to the pickup body 7 so that the center axis of the coils is parallel to the direction of movement of the pickup body. The magnetic circuit 20 described above generates a magnetic flux that interlinks with the drive coil, and together with the drive coil constitutes a linear motor as a moving force applying means for applying a moving force to the moving optical system including the pickup body 7.

Note that the linear motor applies a moving force to a portion of the moving optical system including the pickup body 7 that corresponds to a node of primary transverse vibration.

As shown in FIG. 2, a detection coil 22 is wound around the outer periphery of each drive coil 21 described above so that the center axis of the coil is concentric with the center axis of the drive coil. The magnetic flux described above and emitted from the magnetic circuit 20 of the near motor also interlinks with this detection coil 22. These magnetic circuit 20 and detection coil 22 constitute a speed detecting means for detecting the moving speed of the pickup body 7 and controlling the moving speed. That is, the magnetic circuit 20 constituting the linear motor is also used as the magnetic circuit of the speed detecting means.

As is clear from FIG. 2, the aforementioned steel rollers 8 and 9 are arranged on the yoke 17 side of the magnetic circuit 20.

As shown in FIGS. 1, 3, and 4, a flat rectangular parallelepiped-shaped holding member 25 is attached to the rear end of the frame 1. As shown in FIGS. As shown in FIG. 5, this holding member 25 includes a laser diode 27 as a light emitting element,
A collimator lens 28 that converts the irradiation light emitted from the laser diode into parallel light, a condensing lens 29, and a disk 1
A light receiving element 30 for finally receiving the reflected light from the recording surface of No. 5 to obtain an information signal, shapes the irradiation pattern of the parallel light emitted through the collimator lens 28, guides it to an objective lens to be described later, and performs disk recording. A composite prism 31 that guides the reflected light from the surface to the light receiving element 30, and an astigmatism element 32 that imparts astigmatism to the reflected light for the purpose of detecting the focal error of the light beam emitted toward the disk recording surface. is installed. Further, as shown in FIG. 5, a monitor light-receiving probe is provided on the side of the composite prism 31 to detect a part of the parallel light that is reflected within the composite prism and irradiated to the outside. 34 are arranged.

FIG. 6 shows the view from ■-■ in FIG. 5, and as is clear from both figures, the laser diode 27 is fitted into a counterbore formed in the rectangular plate-shaped holder 35. and is attached to the holding member 25 via the holder. As shown in FIG. 6, a substantially triangular holding plate 36 is provided to prevent the laser diode 27 from being removed from the holder 35, and is fixed to the holder 35 with screws 37.

The rectangular plate-shaped holder 35 described above is movable with respect to the holding member 25 together with the supported laser diode 27 in a plane perpendicular to the optical axis of the laser diode, in this case, in the direction of arrow Y and in the opposite direction. It has become. As a result, the relative positions of the laser diode 27 and the collimator lens 28 within the plane are adjusted, and the parallel light emitted toward the pickup body 7 through the collimator lens 28 is matched with the moving direction of the pickup body. be.

Note that the laser diode 27 and the collimator lens 28
, a composite prism 31, and a holding member 2 that holds them.
5 are collectively referred to as a light source mount.

Furthermore, the light source mount is movable in parallel in the arrow Z direction perpendicular to the optical axis of the parallel light emitted toward the pickup body 7 through the collimator lens 28 and the compound prism 31, and in the opposite direction. Further, the objective lens and its servo drive mechanism, which will be described later, are movable in parallel on the pickup body 7 in the direction of arrow Y and in the opposite direction. As a result, the relative position of the light source mount and the objective lens (described later) is adjusted in the Y-2 plane, and the center axis of the intensity distribution of the parallel light emitted toward the pickup body 7 is adjusted to the position of the light source mount and the objective lens (described later). It can be aligned with the axis.

FIG. 7 shows the view from ■--■ in FIG. 5, and as is clear from both figures, the light receiving element 30 is also attached to the holding member 25 via a rectangular plate-shaped holder 39. This holder 39 has a notch 40 with clearance in the X direction, the Y direction, and the opposite directions thereof, and is engaged with a screw 41, and is fixed to the holding member 25 by the screw 41. Position adjustment is possible within the clearance range.

FIGS. 8 and 9 show a cross section from ■--■ and a cross-section from IX-IX in FIG. 5, respectively.
8. The part that holds the condensing lens 29 and the astigmatism element 32 is a groove 43.44 whose cross section perpendicular to the optical path is V-shaped.
and 45.

As shown in FIG. 5, the composite prism 31 is formed by joining two prisms, a first prism 48 and four second prisms. The first prism 48 is a collimator lens 28
A circular correction surface 50 that is inclined at a predetermined angle with respect to the parallel light obtained through the parallel light and performs circular correction of the parallel light (makes the elliptical irradiation pattern of the parallel light circular); a total reflection surface 51 that totally reflects the parallel light reflected by the total reflection surface, and a polarization reflection surface 52 that transmits the parallel light reflected by the total reflection surface and guides the reflected light from the disk recording surface to the light receiving element 30. There is. Further, the second prisms 4 are attached to this polarized light reflecting surface 52, and work together with the polarized light reflecting surface to guide the reflected light from the disk recording surface to the light receiving element 30. The polarization reflecting surface 52 extends widely to serve as a reference surface, and by using the reference surface as a reference, the second prism 49 and the like can be easily positioned.

In addition, as shown in FIG. 5, the collimator lens 28
The angle between the parallel light emitted through and this reference plane is 4
It is 5°. This makes the incident optical axis 54 and the outgoing optical axis 55 parallel to the composite prism 31, making it easy to arrange the laser diode 27 and the light receiving element 30.

As shown in FIG. 3, the pickup body 7 includes:
A total reflection prism 57 is provided as a guide means for bending the optical path of parallel light emitted through the collimator lens 28 and compound prism 31 at right angles. Also,
As shown in FIGS. 1 and 2, the pickup body 7 includes an objective lens 58 for focusing the parallel light that has passed through the total reflection prism 57 onto the recording surface of the disk 15 as a minute spot light; The objective lens includes a holder 59 and a support member 60 (shown in the first figure), and the objective lens is
2) in the direction of arrow F) and in the direction perpendicular to this (direction of arrow T)
The objective lens consists of an objective lens support mechanism that supports the lens movably in the direction, a magnetic circuit consisting of a magnet 62 and a yoke 63, and a coil (not shown) wound around a holder 59 so that the magnetic flux from the magnetic circuit interlinks with the objective lens support mechanism. A driving source is provided that applies a force to move the lens 58 in the two directions. Note that this drive source and the objective lens support mechanism described above are collectively referred to as a servo drive mechanism. That is, the servo drive mechanism drives the objective lens 58 using electromagnetic force.

As shown in FIG. 4, a flexible printed circuit board 65 is provided for supplying a drive current to the servo drive Fa groove mounted on the pickup body 7. The print board is bent in a U-shape in its thickness direction, and is arranged within the movement locus of the pickup body 7 so that its thickness direction is parallel to the recording surface of the disk 15. .

As shown in FIGS. 1, 3, and 4, a turntable 66 is provided in front of the pickup body 7 and rotates while supporting the disk 15. As shown in FIGS.

Effects of the Invention As detailed above, the optical information recording and reproducing apparatus according to the present invention includes a moving optical system including an objective lens (58), a servo drive mechanism, and a longitudinal holding member (pickup body 7) that holds these; supporting means for supporting both end portions of the holding member and guiding it along the recording surface of the recording medium;
The moving optical system has a moving force applying means for applying a moving force to the moving optical system, and the moving force applying means applies a moving force to a portion of the moving optical system corresponding to a node of primary transverse vibration.

Therefore, the moving optical system does not cause lateral vibration due to resonance, and information can be reproduced or recorded smoothly.

[Brief explanation of the drawing]

FIG. 1 is a plan view of the internal structure of the main part of the optical information recording/reproducing apparatus according to the present invention, FIGS. The figure is an IV-IV arrow view with respect to FIG. 3, FIG. 5 is a partially detailed view of the internal structure, and FIGS. 6 to 9 are explanations of the symbols of main parts. 5.6...Support Rail 7...Pickup body 8.9...Steel roller 13...Spring member 15...Disc 16...Longitudinal magnet 17.18... ... Longitudinal yoke 20 ... Longitudinal magnetic circuit 21 ... Drive coil 22 ... Detection coil 25 ... Holding member 27 ... Laser diode 28 ... ... Collimator lens 29 ... Condenser lens 30 ... Light receiving element 31 ... Compound prism 32 ... Astigmatism element 34 ...・Monitor light receiving element 43, 44, 45... V-shaped groove 48...
・First prism 49...Second prism 50...Circular correction surface 51...Total reflection surface 52...Polarization reflection surface 58...・Objective lens

Claims (1)

[Claims] a plurality of optical elements including a light emitting element and an objective lens that focuses irradiation light emitted from the light emitting element onto a recording surface of a recording medium; a servo drive mechanism that servo drives the objective lens; and at least the objective lens and the servo drive mechanism. a longitudinal holding member holding the holding member; supporting means supporting the holding member movably along the recording surface; and a moving force that applies a moving force to the moving optical system including the objective lens, the servo drive mechanism, and the holding member. applying means, the supporting means supports both end portions of the holding member, and the moving force applying means applies a moving force to a portion corresponding to a node of primary transverse vibration of the moving optical system. An optical information recording and reproducing device.