JPH01158625A - Optical recording and reproducing device - Google Patents

Abstract

PURPOSE:To attain a thinning by making a light beam emitted from a fixed optical system and incident on a fixed reflecting mirror nearly parallel to a medium face and providing the fixed optical system, a turning member, a galvanomirror, etc., on a plane. CONSTITUTION:The light beam coming from a fixed optical system 1 separated from a turning member 3 is reflected by a galvanomirror 2, made incident on an objective lens through the fixed reflecting mirror and a light spot is formed on the face of a medium 7. The optical system 1, the member 3 and the mirror 2 are constructed on nearly the same plane so that the light beam coming from the optical system 1 and made incident on the fixed reflecting mirror through the mirror 2 may become nearly parallel to the recording medium face of the medium 7 at this time. The turning center of the mirror 2 and the turning center of the member 3 are made nearly coincident so that the light beam made incident on the objective lens 6 may not fluctuate at the time of driving the member 3 in a tracking direction T.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an optical recording and reproducing device for optically recording and reproducing information.

A conventional optical recording/reproducing device is composed of optical elements such as a semiconductor laser, a collimating lens, and a half mirror 8, and includes a means for detecting a focus error signal on a disk-shaped recording medium such as a magneto-optical disk, and a means for detecting a focus error signal on a disk-shaped recording medium such as a magneto-optical disk. an optical system comprising means for detecting the above tracking error signal and information detection means for detecting information on the disk-shaped recording medium; and an objective lens for forming a light spot on the disk-shaped recording medium; a mechanism for driving the disk-shaped recording medium in a focusing direction (F) perpendicular to the recording medium surface and in a radial tracking direction (T) parallel to the recording medium surface; Information is optically recorded and reproduced on a disc-shaped recording medium.

A conventional optical recording/reproducing apparatus of this type had a configuration as shown in FIG.

As shown in FIG. 3(A), a hollow rotating shaft 22 is connected to the housing 1 through bearings 15a and 15kl in the rotating member 3.
It is fixed at 9. A lens holder 6 to which an objective lens 6 is attached is installed at one end of the rotating member 3 via two parallel leaf springs 4a and 4b. The light beam 23 emitted from the fixed optical system 1 fixed separately below the housing 19 passes through the center of rotation of the rotating shaft 22 and reaches both end surfaces 241L, 2 of the prism 21 attached to the rotating member 3.
It is configured so that it is totally reflected by the beam 4b and enters the objective lens 6. Drive in the tracking direction T is performed by the rotating member 3.
A tracking drive magnet 12 is integrally fixed to a rotation yoke 20 that rotates around a rotation axis 22, and a tracking drive coil 11 is integrally attached to a magnetic yoke 18 fixed to a housing 19. It is obtained by rotating around the rotation axis 22 using an electrodynamic transducer arranged with the . As shown in FIG. 3 (8), driving in the focus direction F is performed by moving the focus attached to the lens holder 5 into the gap 17 of the magnetic circuit consisting of the focus drive magnet 1° and the magnetic yokes 1esa and 16b. The driving coil 9 is disposed and the electrodynamic transducer causes the objective lens 6 to be attached and the lens holder 5 to translate through two parallel leaf springs 4a and 4b. Here, focus drive coil 9 and air gap 1
7 is formed in an arc shape centered on the rotation axis 22 in the tracking direction T.

Optical recording and reproducing devices record and reproduce information at any location on the recording medium, so it is necessary to shorten access time, and making the entire device smaller and thinner is an important issue. .

The optical recording/reproducing apparatus having the configuration shown in FIG. 3 uses optical elements such as a semiconductor laser, a collimating lens, and a half mirror, as well as focus error signal detection means, tracking error signal detection means, and
By separating the fixed optical system 1 comprising the information signal detection means from the rotating member 3, the weight of the movable part is reduced and the access time is reduced. In order to prevent the light beam 23 incident on the objective lens 6 from fluctuating when the rotating member 3 is driven in the tracking direction T, the light beam 23 from the fixed optical system 1 passes through the rotation center of the rotating shaft 22 and passes through the prism. 21 so that the light enters the objective lens 6. As a result, the light beam 23 always remains on the rotating member 3.
The optical properties of the objective lens 6, such as its ability to form a light spot on the recording medium, are not affected by the rotation angle.

Problems to be Solved by the Invention However, in the optical recording/reproducing device having the above configuration, the light beam 23 from the fixed optical system 1 passes through the center of rotation of the rotating shaft 22. The member 3 and the housing 19 are stacked in the focus direction F.

Therefore, in order to achieve a reduction in the overall thickness of the optical recording/reproducing device, the above-mentioned configuration basically has a limit.

The present invention provides an optical recording/reproducing device that can reduce the overall thickness of the device while reducing access time.

Means for Solving the Problems The technical means of the present invention for solving the above-mentioned problems is that the optical system and the rotating member are arranged so that the light beam emitted from the optical system is aligned in the tracking direction. The light enters the objective lens through a galvanometer mirror that has a mechanism that can rotate only in the direction T, and a fixed reflection mirror attached to the rotating member, and then exits from the optical system and is fixedly reflected via the galvanometer mirror. A configuration in which the rotating member and the galvanometer mirror 1 optical system are arranged substantially on the same plane so that the light beam incident on the mirror is substantially parallel to the recording medium surface of the disk-shaped recording medium on which information is recorded and reproduced. It becomes.

Effects of the present invention By separating the optical system, which occupies a considerable proportion of the weight, from the rotating member, the weight of the movable parts can be reduced, shortening the access time, and at the same time, the optical system can be separated from the rotating member. The emitted light beam is incident on the objective lens via a galvanomirror having a mechanism that can rotate only in the tracking direction T and a fixed reflection mirror attached to the rotating member, and is emitted from the optical system. The rotating member and the galvano mirror 2 optical system are arranged so that the light beam incident on the fixed reflection mirror via the galvano mirror is approximately parallel to the recording medium surface of the disc-shaped recording medium on which information is recorded and reproduced. By arranging them on the same plane, the entire optical recording/reproducing device can be made thinner.

Example Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 1(M) is a front view showing an embodiment of the optical recording/reproducing apparatus of the present invention, and FIG. 1(B) is a sectional view showing the embodiment of the optical recording/reproducing apparatus of the present invention.

In FIG. 1(B), the rotating member 3 is attached to one end of a shaft 14 via a bearing 16, and the other end of the shaft 14 is fixed to the base 13.

The rotating member 3 includes a galvanometer mirror 2 having a mechanism capable of rotating only around an axis X parallel to the focus direction F, a fixed reflection mirror 8, and an objective lens drive that drives the objective lens 6 in the focus direction F. The device includes a tracking drive coil 11.

The objective lens driving device includes an objective lens 6 and an objective lens 6.
a lens holder 6 that holds the lens, and a focus drive coil 9.
and two parallel plate springs 41L and 4b, one end of which is attached to the lens holder 6, and the other end is attached to a part of the rotating member 3. .

Driving in the tracking direction T and the access direction AC is obtained by rotation about the shaft 14 by an electrodynamic transducer consisting of a surface magnetic field generated from the tracking drive magnet 12 and the tracking drive coil 11.

The drive in the focus direction F is performed by the focus drive magnet 1Q.
This is achieved by a surface magnetic field generated by an electrodynamic transducer consisting of a focus drive coil 9 and a translational movement via parallel plate springs 4a and 4b.

As shown in FIG. 1 (A,), a light beam 23 emitted from a fixed optical system 1 separated from a rotating member 3 is transmitted to a galvano mirror 2.
As shown in FIG. 1(B), the light beam is incident on the objective lens 6 via the fixed reflection mirror 8 to form a light spot on the recording medium surface of the disk-shaped recording medium (hereinafter referred to as disk 7). At this time, a light beam 2 exits from the fixed optical system 1 and enters the fixed reflection mirror 8 via the galvanometer mirror 2.
3 so that it is approximately parallel to the recording medium surface of the disc.
The fixed optical system 1, the rotating member 3, and the galvanometer mirror 2 are arranged on substantially the same plane.

Therefore, the fixed optical system 1 is separated from the rotating member 3, and the weight of the movable part is reduced, thereby shortening the access time. Due to this arrangement, the entire optical recording/reproducing device can be made thinner.

In addition, the rotation center of the galvanometer mirror 2 and the rotation center of the rotation member 30 are made to substantially coincide so that the light beam 23 incident on the objective lens 6 does not fluctuate when the rotation member 3 is driven in the tracking direction T. There is.

Therefore, as shown in FIGS. 2(A) and 2(B), by adjusting the rotation angle of the galvanometer mirror 2, the light beam 23 is always spread over the entire recording area of the disk 7, regardless of the rotation angle of the rotating member 30. Since the light is incident on the fixed reflection mirror 8 at a constant angle, optical characteristics such as the ability of the objective lens 6 to form a light spot on the disk T are not affected by the rotation angle. Furthermore, in tracking servo in a high frequency band, the galvanomirror 2 does not drive the entire rotating member 3.
Needless to say, efficient and stable tracking servo can be achieved by driving the servo.

Effects of the Invention The present invention is an optical recording and reproducing device that has a function of optically recording and reproducing information on a disk. an objective lens driving device fixed to the rotating member, comprising a rotating member equipped with a mechanism for driving in the access direction and a mechanism for driving an objective lens in the focus direction for irradiating a light spot onto the disk; and a fixed reflecting mirror which is fixed on the rotating member and which makes the light beam emitted from the fixed optical system enter approximately parallel to the optical axis of the objective lens. The fixed optical system, rotating member, and galvano mirror are located so that the light beam that enters the fixed reflecting mirror through the mirror is approximately parallel to the recording medium surface of the disk, and in a position that does not interfere with each drive. By arranging them on substantially the same plane, it is possible to simultaneously shorten access time and make the entire device thinner.

[Brief explanation of the drawing]

FIG. 1 (person) is a front view of an optical recording and reproducing apparatus according to an embodiment of the present invention, FIG. 1 (B) is a sectional view of the same, and FIG.
B) is a front view showing the effects of an optical recording/reproducing device according to an embodiment of the present invention, FIG. Chaos, diagram. 1... Fixed optical system, 2... Galvano mirror 13... Rotating member, 4a, 4b...
・Plate spring, 6...Lens holder, 6...
・Objective lens, completed...Disc, 8...
・Fixed reflection mirror, 9... Focus drive coil, 10... Focus drive magnet, 11...
... Tracking drive coil, 12 ... Tracking drive magnet, 13 ... Base, 14
...shaft, 16...bearing. Name of agent: Patent attorney Toshio Nakao and 1 other person1-
- Fixed optical string 2 - Galvano mirror 3 - Eye # member 7 - Nice AJ 2 - Luba mirror - 3 - Rotating part shuttle 1 spring 7 - Nyzuku 8 - Fixed Ii, projection mirror 9 - - Focus 1 section moving coil 13-Base I--Ikko Uito S--Lens holder<A+'--Katakan lens I6σ, l Otb-Magnetic Goke 17-Kitaku gap 18-Kyo low yoke/? --Hakusing f'O-m-Rotating yoke 2/-...Puzozumgo-Rotating wheel Fig. 3 23-Light beam F! 4a, 24b---Psosm s side (A) Fig. 3

Claims (2)

[Claims] (1) An optical recording and reproducing device having a function of optically recording and reproducing information on a disc-shaped recording medium, which is composed of optical elements such as a semiconductor laser, a collimating lens, and a half mirror, and is a fixed optical system comprising means for detecting a focus error signal on the disc-shaped recording medium, means for detecting a tracking error signal on the disc-shaped recording medium, and means for detecting an information signal on the disc-shaped recording medium; a galvanometer mirror having a mechanism capable of rotating around an axis substantially parallel to the optical axis direction perpendicular to the recording medium surface of the medium; and the recording medium surface about the axis substantially parallel to the optical axis direction. a rotating member having a mechanism for rotating in a substantially radial direction in a direction substantially parallel to the rotating member; and an objective lens fixed to the rotating member for forming a minute light spot on the surface of the recording medium. an objective lens driving device equipped with a mechanism for driving the optical axis in the optical axis direction; and an objective lens driving device that is attached to the rotating member and for causing the light beam emitted from the fixed optical system to be incident approximately parallel to the optical axis of the objective lens. a fixed reflecting mirror, such that a light beam emitted from the fixed optical system and incident on the fixed reflecting mirror via the galvanometer mirror is approximately parallel to the recording medium surface, and each 1. An optical recording/reproducing device, wherein the fixed optical system, the rotating member, and the galvano mirror are arranged on substantially the same plane at a position that does not interfere with the driving of the optical recording/reproducing device. (2) Claim 1, characterized in that the rotation center of the galvanometer mirror and the rotation center of the rotating member are substantially aligned.
The optical recording/reproducing device described in .