JP2653147B2 - Optical recording / reproducing device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical recording / reproducing apparatus for recording / reproducing or recording / reproducing / erasing information using an optical recording medium such as an optical disk, and in particular, to an optical recording / reproducing apparatus. The present invention relates to an improvement in an optical recording / reproducing apparatus capable of moving an optical head at high speed and accurately.

[Prior Art] As this kind of optical recording / reproducing apparatus, as shown in FIG. 4, a semiconductor laser (a) and this semiconductor laser (a) are used.
Collimator lens (b) for converting the diffused laser light from the laser beam into parallel laser light, and a beam shaping prism (c) for converting the spot shape of the laser light from an elliptical shape to a substantially circular shape
A beam splitter (e) for separating incident laser light incident on the optical recording medium (d) and reflected laser light reflected from the optical recording medium (d), and a straight line passing through the beam splitter (e). A quarter-wave plate (f) for converting circularly polarized laser light into circularly polarized light;
An objective lens (g) for converging the laser beam passing through the wavelength plate (f) on a converging surface of the optical recording medium (d); and a reflected laser beam separated by the beam splitter (e) for a tracking error signal and a focusing error. 2. Description of the Related Art There is known an apparatus in which a main part is constituted by a signal and a cylindrical lens (j) incident on a four-division PIN photodiode (h) for obtaining a reproduced RF signal.

And in such an optical recording / reproducing device,
An optical head including an optical system such as an objective lens (g) for recording information spirally or concentrically on the surface of the optical recording medium (d), or reproducing the recorded information, is mounted on the optical recording medium (d). While moving along the track direction, it is necessary to move the optical head in the focus direction in order to cope with surface runout of the optical recording medium (d).
Conventionally, the following drive systems have been used.

First, as an example, as shown in FIGS. 5 and 6, an optical head (He) provided near an optical recording medium (d) and provided with a driving coil (p1) moves in a track direction and a focus direction. A movable platform (k) movably mounted and having a substantially H-shaped cross section, a carriage (m) provided on the lower end surface of the movable platform (k) for movably supporting the movable platform (k), and a straight line A pair of bobbins (q1) and (q2) each having a bearing (n), a driving coil (p2) wound on both sides of the moving table (k), and a bobbin (q1) (q2) A pair of magnetic yokes (r1) and (r2) inserted into the cylindrical portion, and track control permanent magnets (s1) to (s4) provided on the upper and lower sides of each bobbin (q1) and (q2); Focus control permanent magnets (s5) and (s6), which are disposed along the length direction of the permanent magnets (s1) and (s4). The main part is constituted by a magnetic holder (t) holding these permanent magnets (s1) to (s6), and energizing the drive coil (p1) of the optical head (He). This drive coil (p
The optical head (He) is moved in the focus direction of the optical recording medium (d) by using the electromagnetic force acting on 1) to perform focus control, and the drive coil (p2) for the bobbins (r1) (r2) is operated. ) Is moved in the direction of arrow A by using the electromagnetic force acting on the driving coil (p2) upon energization of the driving coil (p2), and the optical head (He) mounted on the moving table (k) is moved. ) Is reciprocated along the track direction of the optical recording medium (d).

On the other hand, as another example, as shown in FIG. 7, an optical head (He) which is arranged near the optical recording medium (d) and floats by an air flow accompanying rotation of the optical recording medium (d); A spring-shaped suspension (v) that supports the optical head (He) so as to be able to advance and retreat with respect to the optical recording medium (d), and a voice coil motor (w) that holds the base end of the suspension (v) and controls the optical recording medium ( The main part is constituted by the moving member (y) linearly moved in the track direction of d), and the moving member (y) is energized by the drive coil (z) wound around the moving member (y). y) is moved to move the optical head (He) in the track direction of the optical recording medium (d), and the optical head (He) is moved by the air flow acting on the optical head (He). ) Focus is moved in the focus direction Control was performed.

[Problems to be Solved by the Invention] By the way, in the former optical recording / reproducing apparatus incorporating the above-mentioned driving system, focusing is performed by using an electromagnetic force acting on a driving coil (p1) of an optical head (He). There is a problem that the control system becomes complicated due to the configuration for controlling.
As shown in FIG. 6, the optical head (He) is a movable table (k),
The carriage (m), the bobbins (q1) (q2), the magnetic yokes (r1) (r2), the permanent magnets (s1) to (s4), and the like are arranged at positions distant from the drive source (x). Therefore, when moving the optical head (He), this optical head (He)
However, there is a problem that the optical head (He) cannot be quickly and reliably moved to a predetermined position due to unstable driving control.

On the other hand, the latter optical recording / reproducing apparatus has an advantage that the control system is simplified because the focus control is performed using the airflow acting on the optical head (He). Is mounted via a spring-shaped suspension (v) at a position distant from a drive source (x) composed of a voice coil motor (w), a moving member (y), and the like. There is a disadvantage that a moment force is applied to the optical head (He) during the movement of the (He), and there is a problem that the moving operation to a predetermined position cannot be performed quickly and accurately.

[Means for Solving the Problems] The present invention has been made in view of the above problems, and an object thereof is to quickly and accurately reciprocate an optical head in the track direction of an optical recording medium. An object of the present invention is to provide an optical recording / reproducing apparatus which can be moved.

That is, the present invention comprises a reflecting member which is arranged near a rotating optical recording medium, floats by an air flow accompanying the rotation of the optical recording medium, and reflects the condensed light from the light source to the optical recording medium side. An optical head having an objective lens for converging the reflected condensed light on a converging surface of the optical recording medium and having a driving coil wound thereon; and moving the optical head in a floating direction and a track direction of the optical recording medium. A support member that supports the optical head, and a magnet that is provided along the track direction of the optical recording medium and forms a magnetic field line that faces the optical head. The moving operation is performed along the track direction of the recording medium.

In such technical means, the optical head floats in response to an air flow accompanying rotation of the optical recording medium,
In order to efficiently receive the floating pressure from the optical recording medium, a sliding surface and an air introduction surface are formed at least on the bottom side. In order to stabilize the floating movement of the optical head, a concave groove for allowing air to escape along the longitudinal direction of the head, that is, a central escape portion may be formed. In this case, the number and shape of the grooves can be arbitrarily set according to the purpose. In addition, as a material constituting the optical head, a hard material that is lightweight, has good processing accuracy, and is hardly damaged is preferable. Specifically,
Ceramic materials, amorphous carbon, barium titanate, potassium titanate and the like can be used. However, when a conductive material such as amorphous carbon is applied, it is necessary to perform an insulating treatment such as coating an insulating film on at least a portion where the driving coil is wound.

A method of mounting a reflecting member such as a mirror and a prism and an objective lens on the optical head is arbitrary.
This optical head is composed of one floatable member, and a drive coil is wound around a part of the optical head, and a method of incorporating the objective lens or the like in another part is searched. It is also possible to adopt a method in which two floating members are used, a driving coil is wound around one of them, and an objective lens or the like is incorporated into the other. In this case, in order to suppress the generation of the moment force during the movement, it is necessary to mount the two members so as to be moved on the same plane.

On the other hand, as for the support member for supporting the optical head, any configuration is possible as long as the optical head is supported so as to be movable in the floating direction and the track direction of the optical recording medium. And a resilient member such as a spring that is disposed between the moving body and the optical head and connects these members to each other.

Further, the magnet forming the line of magnetic force toward the optical head side is constituted by a permanent magnet such as a rare earth iron-based magnet or an electromagnet,
It is arranged along the track direction of the optical recording medium,
An electromagnetic force is applied to the drive coil by energizing the drive coil wound around the optical head, and the optical head is moved in the track direction of the optical recording medium by the electromagnetic force.

[Operation] According to the technical means described above, the optical head itself is directly moved in the track direction of the optical recording medium by the electromagnetic force generated by energizing the driving coil wound around the optical head. The optical head and the drive source are integrated, and it is possible to prevent the generation of a moment force during movement.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

That is, as shown in FIGS. 1 to 3, the optical recording / reproducing apparatus includes an optical head (2) arranged near an optical recording medium (1) and an optical recording medium (2). (1) a support member (3) that movably supports the focus direction and the track direction, and a pair of permanent magnets (40) and (41) that are arranged in parallel with each other along the track direction of the optical recording medium (1). The main part is constituted by.

First, the optical head (2) is formed of a ceramic material, and a driving coil (21) is wound around a central concave portion (20), and a floating body ( 22) and an auxiliary body (25) mounted on the center side of the optical recording medium (1) of the floating body (22) and having a prism (23) and an objective lens (24) mounted thereon. .

On the other hand, the support member (3) has an engagement groove (30) on an opposite side provided along the track direction of the optical recording medium (1).
A pair of guide members (32) and (33) formed with (31);
The guide members (32) and (33) are disposed between the guide members (32) and (33), and engage on both sides thereof with the engagement grooves (30) and (31) of the guide members (32) and (33) via the bearing (34). Joint part (35) (36)
And a moving body (37) formed of a lightweight aluminum alloy material, and six spring members interposed between the moving body (37) and the floating body (22) and connecting these members to each other. (38) to (38).

Further, the permanent magnets (40) and (41) are supported by a support member (3).
And a belt-shaped rare-earth iron-based permanent magnet attached to holding members (42) and (43) arranged in parallel with the guide members (32) and (33).
From 1), magnetic lines of force directed toward the floating body (22) are formed.

In the optical recording / reproducing apparatus thus configured, laser light from a light source (not shown) provided on the apparatus main body side is incident on the prism (23) of the optical head (2), and the prism (23) ) Is converged on the converging surface of the optical recording medium (1) by the objective lens (24) to record, reproduce, and erase information.

In this device, an electromagnetic force acts on the drive coil (21) by energizing the drive coil (21) wound around the floating body (22) through a lead wire (not shown). The floating body (22) itself is reciprocated along the track direction of the optical recording medium (1) by electromagnetic force, while the floating body (22) floats due to the airflow acting on the floating body (22), Optical recording medium (1) and floating body (2
2) That is, focus control is performed while keeping the distance between the optical heads (2) constant.

As described above, in this optical recording / reproducing apparatus, the floating body (22) itself constituting the optical head (2) is directly moved in the track direction of the optical recording medium (1). Drive coil (21) driven by this
It is possible to prevent the generation of a moment force when the optical head (2) moves when the driving sources such as are integrated.

Therefore, the vibration characteristic is improved and the track drive control is stabilized, so that the optical head (2) is quickly moved to a predetermined position.
In addition, there is an advantage that the moving operation can be performed accurately. Incidentally, following the movement of the optical head (2), the moving body (37) which constitutes a part of the support member (3) also moves in the same direction. The body (3) is slightly displaced via the spring members (38) to (38).
7) may vibrate. However, this moving body (3
7) is lighter than the optical head (2), so that the vibration does not hinder the operation of the optical head (2).

Further, since a conventional drive coil for focus control is not required, and the optical head (2) is reduced in weight,
There is an advantage that the driving force is reduced correspondingly and the movement accuracy is improved.

[Effects of the Invention] As described above, since the optical head itself is directly moved in the track direction of the optical recording medium by the electromagnetic force accompanying the energization of the driving coil wound around the optical head,
The optical head and the drive source are integrated, and it is possible to prevent the generation of a moment force during movement.

Therefore, the driving force applied to the optical head is stabilized, and the optical head can be quickly and accurately moved to a predetermined position.

[Brief description of the drawings]

1 to 3 show an embodiment of the present invention. FIG. 1 is a partial perspective view of an optical recording / reproducing apparatus according to the embodiment, and FIG.
FIG. 3 is a sectional view taken along the line II-II of FIG. 1, and FIG. 3 is a sectional view taken along the line III-I of FIG.
FIG. 4 shows a cross-sectional view of the II plane, FIGS. 4 to 7 show a conventional example, FIG.
FIG. 5 is a perspective view showing an example of a drive system of the optical head,
FIG. 6 is a sectional view taken along the line VI-VI, and FIG. 7 is a perspective view showing another example of the drive system. [Description of symbols] (1) Optical recording medium (2) Optical head (3) Support member (21) Driving coil (23) Prism (24) Objective lens (40) (41) ... permanent magnet

Claims (1)

(57) [Claims] An optical recording medium is arranged near a rotating optical recording medium, and floats by an air flow accompanying rotation of the optical recording medium.
A reflecting member for reflecting the condensed light from the light source toward the optical recording medium and an objective lens for converging the condensed light reflected by the reflecting member on the converging surface of the optical recording medium are mounted, and the driving coil is wound. An optical head, a support member for supporting the optical head movably in a floating direction and a track direction of the optical recording medium, and a magnet provided along the track direction of the optical recording medium and forming a magnetic line of force directed toward the optical head. An optical recording / reproducing apparatus, comprising: moving an optical head along a track direction of an optical recording medium by an electromagnetic force generated by energizing the driving coil.