JPS6313139A - Optical information recording and reproducing device - Google Patents

Abstract

PURPOSE:To keep the accuracy of the movement of a holding member for a long time by placing one roller rolling on a support rail out of the two rollers rolling on support rails in the direction opposite to that of the gravity with respect to the other roller. CONSTITUTION:Plural rollers 8, 9 supporting a pickup body 7 being a holding member holding an objective lens and its servo drive mechanism at three-point to a couple of support rails 5, 6 and a spring member 13 pressing the roller 8 of the point of the three point support onto the support rail 5 are provided. Further, the roller 8 of one-point support is always placed in the anti-gravity center direction with respect to the roller 9 of the two-point support. Thus, the spring member 13 being the pressing means does not receive a large gravity such as the gravity of the body 7, the spring member 13 is not deteriorated, the accuracy of the movement of the body 7 is assured and the recording/ reproduction of information is applied stably for a long time.

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 an example of the support means, a pair of support rails extending along the disk recording surface and in the moving direction of the holding member and located on both sides in the moving direction, and each supporting rail attached to the holding member are provided. Some consist of a plurality of rollers that roll on top. In order to stabilize the movement of the holding member, the number of rollers and their positions are set so that the holding member is supported at three points on both support rails. That is, one side of the holding member is supported by one support rail at one point, and the other side is supported by the other support rail at two points. In this case, in order to move the holding member with high precision, each of the rollers is pressed against each support rail.

Specifically, only the roller on the one point side is movable within a predetermined range relative to the holding member in the direction of movement of the holding member, that is, the direction perpendicular to the extending direction of both support rails, and the roller is moved by a spring. The one support rail is pressed by a pressing means such as a member. As a result, not only this roller but also the rollers on the two points side are pressed against the other support rail by the reaction force.

In the conventional optical information recording and reproducing device having the support means configured as described above, the optical information recording and reproducing device is installed so that the roller on the one point side is positioned in the direction of gravity with respect to the roller on the two point side. In this case,
The spring member serving as the pressing means that urges the roller on the one-point side receives a large weight from the holding member, etc., and the spring member deteriorates quickly, impairing the accuracy of movement of the holding member, and the information This has the disadvantage of having an adverse effect on playback or recording.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and its purpose is to provide an optical information recording/reproducing device that can stably reproduce or record information over a long period of time. It is.

The optical information recording/reproducing device according to the present invention includes a plurality of rollers for supporting a holding member holding an objective lens and its servo drive mechanism at three points with respect to a pair of support rails, and one point of the three points of support. It has a pressing means for pressing a side roller against one of the support rails, and is characterized in that the roller on the one point side is always positioned in the anti-gravity direction with respect to the roller on the two point side. .

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 in a housing (not shown) of the optical information recording/reproducing device, and has four leg members 2 and 3 attached 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 spaced apart from each other in the direction of movement of the pickup body, and abut 4 on the other support rail 6. As is particularly clear from FIG. 4, the peak-up body 7 is supported at three points by both support rails 5 and 6 via the above-mentioned 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 suppressing 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-gravity 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. This prevents the spring member 13 for pressing the roller 8 against the support rail 5 from receiving a large weight of the pickup body or the like.

In addition, both the above-mentioned support rails 5 and 6 and the steel roller 8.
The spring member 13 and related peripheral small members 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 longitudinal magnet 16 and a longitudinal yoke 1'7, each extending along the direction of movement of the pickup body 7 (the direction of arrow Y and the opposite direction thereof) and being engaged with each other. A pair of longitudinal magnetic circuits 20 consisting of '18 are fixed. 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 moving direction 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 above-mentioned magnetic flux emitted from the magnetic circuit 20 of the near motor also interlinks with this detection coil 22.These magnetic circuits 20 and detection coils 22 detect the moving speed of the pickup body 7 and control the moving speed. In other words, 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 condenser lens 29, a light receiving element 30 that ultimately receives the reflected light from the recording surface of the disk 15 to obtain an information signal, and a collimator lens. A compound prism 31 that shapes the irradiation pattern of the parallel light emitted through 28 and guides it to an objective lens (described later) and guides the reflected light from the disk recording surface to a light receiving element 30, and a light beam emitted toward the disk recording surface. An astigmatism element 32 is attached to give astigmatism to the reflected light for the purpose of detecting the focus error. Further, as shown in FIG. 5, on the side of the composite prism 31, there is a monitor light receiving element 34 for detecting a part of the parallel light that is reflected within the composite prism and irradiated to the outside. is located.

FIG. 6 shows the Vl-Vl arrow view with respect to FIG. 5, and as is clear from both figures, the laser diode 2
7 is fitted into a counterbore formed in a 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
It 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 city 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 two arrow directions 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) in the Y-Z plane is adjusted, and the center axis of the intensity distribution of the parallel light emitted toward the pickup body 7 is aligned with the light of 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 that has a 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 ■-■ to FIG. 5 and a cross-section from IX-IX, 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 a second prism 49. 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 prism 49 is attached to this polarized light reflecting surface 52, and works in cooperation 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; It includes five holders and a support member 60 (shown in the first figure), and the objective lens is supported in its distal axial direction (
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 fluxes of the magnetic circuit interlink. 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 drive current to the servo drive mechanism mounted on the pickup body 7. The printed circuit board is bent into 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, in the optical information recording/reproducing apparatus according to the present invention, the holding member (pickup body 7) holding the objective lens (58) and its servo drive mechanism is mounted on the pair of support rails (5, 6). ) for three-point support, and a pressing means (spring member 13) for pressing the roller (8) at one point of the three-point support against one support rail. The roller (9) on the one point side is always positioned in the anti-gravity direction with respect to the roller (9) on the two point side.

Therefore, the suppressing means, such as the spring member (13), does not receive a large weight from the holding member (pickup body 7), the spring member does not deteriorate, and the accuracy of movement of the holding member is ensured. Information can be reproduced or recorded stably over a long period of time.

[Brief explanation of drawings]

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.
They are an I cross-sectional view, a ■-■ arrow view, a ■-■ cross-sectional view, and an IX-IX cross-sectional view. Explanation of symbols of main parts 5.6...Support rail 7...Pickup body 8.9...Steel roller 13...Spring member 1, - ...Disk 1, :...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 ... Condensing lens 30 ... Light receiving element 31 ... ...Composite prism 32...Astigmatism element 34...Monitor light receiving element 43.44.45...7-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 holding member holding the holding member; supporting means supporting the holding member movably along the recording surface; and moving force applying means applying a moving force to the holding member, the supporting means holding the holding member. a pair of support rails extending in the direction of movement and located on both sides with respect to the direction of movement; a roller that rolls on a support rail; a pressing means that presses the roller against the one support rail; and at least two other rollers rolling on said one support rail, wherein said roller rolling on said one support rail is positioned in an anti-gravity direction with respect to said other rollers. type information recording and reproducing device.