JPH01158626A - Optical recording and reproducing device - Google Patents

Abstract

PURPOSE:To attain the shortening of an access time by arranging plural objective lenses fixed to a turning member to form a minute light spot on a discoid recording medium on nearly a straight line in nearly the radius direction of the medium. CONSTITUTION:Parallel luminous fluxes emitted from a fixed optical system 1 are reflected by a galvanomirror 2, reflected by a mirror 8, after that, made incident on one of objective lenses 6a, 6b and 6c and a light spot is formed on a disk 7. In case of making an access to the innerest periphery of the disk 7, the turning member 3 turns so that the lens 6a may come to the innermost periphery of the disk 7. Simultaneously, the mirror 2 turns so that the light maybe incident on the lens 6a. In making an access to the outermost periphery of the disk 7, the member 3 turns so that the lens 6c may come to the outermost periphery of the disk 7. Simultaneously, the mirror 2 turns so that the light may be made incident on the lens 6c. Thus, a high-speed access can be realized.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an optical recording and reproducing apparatus 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, and includes a means for detecting a focus error signal on the disk-shaped recording medium and a means for detecting a focus error signal on the disk-shaped recording medium. an optical system comprising a means for detecting an error signal and an information detecting 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 such as a magneto-optical disk. , a mechanism for driving the disc-shaped recording medium in a focus direction (CF) perpendicular to the recording medium surface and a tracking direction (T) in a radial direction parallel to the recording medium surface; Information is optically recorded and reproduced on a 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 of the rotating member 3 is fixed to the housing 19 via bearings 152L and 15b. At one end of the rotating member 3, there are two
A lens holder 6 to which an objective lens e is attached is installed via parallel plate springs 4a and 4bi. A 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 24 and 24 of the prism 21 attached to the rotating member 3.
, 24b and enters the objective lens 6.

The driving in the tracking direction T is performed integrally with the rotating member 3,
A moving mechanism in which a tracking direction drive magnet 12 fixed to a rotation yoke 20 rotating around a rotation axis 22 and a tracking drive coil integrally attached to a magnetic yoke 18 fixed to a housing 19 are arranged. This is obtained by rotating the entire rotation axis 22 using an electric type converter.

As shown in FIG. 3 (Bl), driving in the focus direction F is performed by focusing, driving magnet 1o, magnetic yoke 16a,
An electrodynamic transducer in which a focus drive coil 9 attached to the lens holder 5 is arranged in the gap 1T of the magnetic circuit consisting of
, 4b, the lens holder 6 to which the objective lens is attached is translated. here,
The focus drive coil 9 and the gap 1 are formed in an arc shape centered on the rotation axis in the tracking direction T.

Problems to be Solved by the Invention Since optical recording and reproducing devices record and reproduce information at arbitrary positions on a recording medium, shortening the access time has become a very important issue.

The optical recording/reproducing device 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, etc. in order to shorten access time. By separating the fixed optical system 1, which is composed of There is a limit to the increase in driving force, and it has been difficult to achieve an access time comparable to that of a magnetic disk.

The present invention has been made in view of the above-mentioned conventional technology, and an object of the present invention is to provide an optical recording/reproducing device that can significantly shorten access time while achieving miniaturization and thinning of the entire device. That is.

Means for Solving the Problems In order to achieve the above object, the optical recording/reproducing device of the present invention includes a fixed optical system, a rotating member, and a galvanometer mirror provided near the center of rotation of the rotating member. , a driving means provided at one end of the rotating member for driving a lens holder having a plurality of objective lenses disposed approximately in the radial direction of the disk-shaped recording medium in the optical axis direction of the objective lens; It is composed of the same number of fixed mirrors as the objective lens, which is fixed and reflects the light beam from the galvanometer mirror in the direction of the objective lens.

According to the present invention, when accessing any position in the recording area of the disk-based recording medium, the direction of the light beam is changed by the galvanomirror toward the nearest lens, so that the moving distance of the rotating member is Very little amount is required. Therefore, it is possible to significantly shorten access time.

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

FIG. 1(A) and FIG. 1 (inner) are diagrams showing the entire schematic configuration of an optical recording/reproducing apparatus according to an embodiment of the present invention.

In FIG. 1(A), 1 is a fixed optical system, 2 is a galvano mirror, 53 is a rotating member, 4 is a plate spring, 6 is a lens holder, 62L, 6b, 60 are objective lenses, and 7 is a disc-shaped recording medium. One disk, 8, is a mirror. The lens holder 5 is connected to the rotating member 3 via a leaf spring 4.

The light reflecting surface of the galvanometer mirror 2 and the rotating member 3 rotate around an axis X perpendicular to the plane of the drawing. Figure 1 (B) is
Figure 1 (This is a diagram showing the A-A cross section of Al, 8 is a mirror, 9 is a focus drive coil, 10 is a focus drive magnet, 11 is an access drive coil, 12 is an access drive magnet, 13 is a base) , 14 is a shaft, and 16 is a bearing.Mirror 8 is an objective lens 6a.

It is fixed to one end of the rotating member 3 so as to reflect the light beam from the galvanometer mirror 2 toward eb and 6c. In this embodiment, the number of mirrors 8 is the same as that of the objective lens, but this may be replaced by a single mirror having the same number of light reflecting surfaces as the objective lens.

The operation of an embodiment of the optical recording/reproducing apparatus configured as described above will be explained below. Figure 1 (
In A) and FIG. 1(B), light is emitted from a fixed optical system 1, which is composed of optical elements such as a semiconductor laser, a collimating lens, and a photodetector, and has detection means such as a focus error signal, a tracking error signal, and an information signal. The collimated light beam is reflected by the galvanometer mirror 2, and after being reflected by the mirror 8,
The light enters any one of the objective lenses 62L, 6b, and 6G. In the case of FIG. 1(A), a light spot is formed on the disk 7 by the objective lens 6b. .

The access drive coil 11 has one side fixed to the rotation member 3, and in combination with the access drive magnet 12 fixed to the pace 13, generates a driving force for rotating the rotation member 3. The focus/drive coil 9 is wound around the lens holder 6, and in combination with the focus drive magnet 10 fixed to the base 13, the lens holder 5 is connected to the objective lens 6? It is driven in the optical axis direction (focus direction) of L, 6b, and 60 to perform focus control.

FIG. 2 is a diagram showing only the main parts of this embodiment in order to explain its operation. FIG. 2 (λ) shows the case where the innermost circumference of the recording area of the disk 7 is accessed.
In this case, the rotating member 3 is configured such that the objective lens 62L is
Rotate it so that it is at the innermost circumference. Almost simultaneously, the galvanometer mirror 2 rotates so that the light enters the objective lens 62L.

FIG. 2(B) shows the case where the outermost circumference of the recording area of the disk 7 is accessed. In this case, the rotating member 3 rotates so that the objective lens 6c is located at the outermost periphery of the disk. At almost the same time, the galvanometer mirror 2 moves to the objective lens 6.
Rotate so that the light enters at zero.

Conventionally, in order to shorten access time, the main efforts have been to reduce the weight of moving parts and increase the driving force, but these measures have limitations. The present invention aims to shorten access time by shortening the access distance itself. When three objective lenses are used as in this example, compared to the conventional example with one objective lens,
The recording area that each objective lens has is approximately
Since the amount of rotation of the rotation member 30 also becomes smaller, it becomes possible to access any position on the disk 7 at high speed.

Although this embodiment shows the case where three objective lenses are used, any number of objective lenses may be used as needed.

Further, in this embodiment, the galvanometer mirror 2 is shown as being fixed to the fixing member 3, but it may be fixed to the pace 13 if necessary.

Effects of the Invention The present invention provides access means for an optical recording/reproducing device.
By having a fixed optical system, a galvanometer mirror, and a rotating member having multiple mirrors and multiple objective lenses all around, it is possible to access any position in the recording area of a disc-shaped recording medium at high speed. This makes it possible to realize an excellent optical recording/reproducing device that can significantly shorten access time, which has been difficult with conventional methods.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of an optical recording/reproducing device according to an embodiment of the present invention, and FIG. 2 is a schematic diagram of main parts for explaining its operation.
FIG. 3 is a schematic diagram of a conventional optical recording/reproducing device. 1... Fixed optical system, 2... Galvano mirror 13... Rotating member, 4... Leaf spring, 6... Lens holder , 62L, 6b, 60
...Objective lens, 7...Disc, 8.
...Mirror, 9...Focus drive coil, 1o...Focus drive magnet, 11...
... Access drive coil, 12 ... Access drive magnet, 13 ... Base, 14 ...
...Shaft, 15...Bearing. Name of agent: Patent attorney Toshio Nakao and 1 other person/
--One fixed nine-pot thread 2-Force urban mirror 3-One moving member 4-Form spring 5-One-lens \no-nu 3-m-mirror 9-m-focus! 5 ['l Coil 2 and 10 ---Focus drive general magnet 11 ---Ax, station motion ∆ 12 ---Ax, cantering M7 magnet) 3 ---'\゛- S+4-m-Shaft 15-11 Glaze receiver 1A Fig. 1 CB) Fig. 2

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; It has a mechanism that can rotate about an axis substantially parallel to the optical axis direction perpendicular to the recording medium surface of the medium, and the light beam from the fixed optical system is directed to the recording medium surface of the disk-shaped recording medium. a galvanometer mirror that reflects the light in an arbitrary direction in a plane substantially parallel to the optical axis, and a substantially radial direction of the disk-shaped recording medium in a direction parallel to the recording medium surface about the axis substantially parallel to the optical axis direction. a rotating member equipped with a mechanism for driving the disc-shaped recording medium; and a plurality of objective lenses fixed to the rotating member for forming a minute light spot on the disc-shaped recording medium; an objective lens driving means having a mechanism for driving a lens holder disposed substantially linearly in a radial direction in the optical axis direction; and an objective lens driving means fixed to the rotary member to direct the light beam emitted from the fixed optical system to the objective lens. An optical recording/reproducing device comprising the same number of mirrors as the objective lens for making the light incident substantially parallel to the optical axis of the object. (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 .