KR100590182B1 - A light beam mirror system in an optical pick-up apparatus - Google Patents

Abstract

Disclosed is a technical problem to achieve a light reflecting device for correcting the optical axis with a predetermined light reflecting device as a conventional galvano mirror.

First refractive means 221 for vertically refracting the light of the horizontally incident optical system unit at a predetermined position; And a second refracting means 252 provided to be secondly refracted without changing the optical axis along the tip of the swing arm 200 in which the vertically refracted light is rotated upward from the first refracting means 221. Solve as a device.

A light incidence and reflection system without correction of the optical axis is implemented between the separated optical system unit and the tip of the rotating swing arm.

Light reflector, optical axis, swing arm

Description

A light beam mirror system in an optical pick-up apparatus

1 is a schematic diagram showing an optical recording / reproducing apparatus of a swing arm type in which a conventional optical system unit is separated.

Figure 2a is a cross-sectional view of a wide-angle position detection device using a conventional galvano mirror, Figure 2b is a wide-angle change diagram showing the cause of the optical axis fluctuation caused by the rotation of the conventional refractive means.

3 is a schematic diagram of an optical pickup device of a swing arm type in which the light reflecting device of the present invention is implemented.

4 is a cross-sectional view showing a light refractive state of the light reflecting device of the present invention.

※ Explanation of code for main part of drawing

200: swing arm ..... 210: fixed holder

211: Arc-Type Craftsman ...

213: Shaft work ............... 220: Center shaft

221: first refraction means ...... 230: pivot bearing

231: Construction work ............... 232 ball

240: Shaft ............... 242: Third guide ball

243: Connecting groove ........... 250: Rotating holder

251: Legs ............... 252: Second Refraction Way

253: Fourth guide ... 260: Optical unit

270: base

The present invention relates to a light reflecting apparatus of an optical pickup apparatus, and more particularly, to a light reflecting apparatus in which light incident from an optical system unit is transmitted to a swing arm without a change in an optical axis during rotation of a swing arm.

The optical recording / reproducing apparatus includes an optical pickup for detecting the light returned from the disk after the laser light is incident, and a sending mechanism for moving the optical pickup.

At this time, the transmission mechanism is a linear tracking method for moving the optical pickup in the radial direction of the disk by the rack-pinion or a predetermined motor (VCM), and by rotating the swing arm equipped with the objective lens using the motor (VCM) and the pivot bearing It is divided into swing arm type that rotates the inner and outer circumference of the disk within a certain angle.

The linear tracking method is a two-stage structure in which the tracking position is detected by the movement of the entire optical pickup and the fine adjustment is performed by the radial movement of the objective lens. This tracking method requires the tracking servo circuit to have two systems for optical pickup transmission drive and tracking coil drive.Compared to the swing arm method, the configuration of the yoke, the installation of the guide shaft, the installation of the transfer bearing and the drive system and suspension of the objective lens The back is complicated.

In the swing arm method, the optical pickup is positioned at the distal end and circularly moved in the radial direction of the disc with the center of gravity as the axis.

In this method, since the objective lens is moved in the up and down optical axis directions, a motor such as transferring the optical pickup is not used. In addition, as a means for determining the position of the track, the swing arm method is capable of small size and light weight, and its structure is simple, compared to the form in which the transfer unit equipped with the head or the objective lens goes straight.

However, since the stroke is smaller than the linear tracking method and is suitable for small and medium loads, it is difficult to mount the optical system unit on the swing arm of the rotating body in the recording / reproducing apparatus using the optical system. There is a disadvantage of poor performance.

The swing arm rotates at an angle about the base axis. Between the central axis of the base and the center of rotation of the swing arm, the friction is reduced by using a pivot bearing and the rotation force is provided by the VCM (motor). Therefore, as the pivot bearing or the set screw is located at the rotation center of the swing arm, it is difficult to arrange the optical parts.

1 is a schematic view showing an example of an improved optical recording / reproducing apparatus that improves the weight increase of the shaft of the swing arm method and solves the problem of the optical component.

The optical recording / reproducing apparatus according to this figure is a means for maintaining an optical axis in transmitting or receiving light from an optical system unit 140 fixed to a base during search or tracking to an objective lens located at the end of the swing arm 110. Galvanometer (Mirror, 120) using the principle of the galvanometer (Galvano Metor) is used on the central axis of the swing arm.

That is, the light emitted from the optical system unit 140 is reflected by the galvanometer mirror 120 located on the central axis to the refraction means and the objective lens at the end of the swing arm 110, and then to the HGA (Head Gimber Ass'y). The mounted objective lens forms a spot for recording or reproducing information on the disk, and the light rays reflected on the disk surface are returned to the optical system unit 140 along the incident optical axis to read a signal by the light receiving unit photodiode.

2A shows an optical axis holding means using the galvano mirror 120 as described above. The optical pick-up device of this figure basically fixes the pivot bearing 160 to the fixed shaft 180 fixed on the base 190 and the C-axis of the swing arm 110 around it.

Install using (170). The swing arm 110 may be integrally provided with the rotary holder 150 provided with the galvano mirror 120.

2B shows the change of the reflection angle according to the rotation of the refraction means on the plane.

The optical axis maintenance support of the optical pickup apparatus to which the optical axis holding means according to these drawings is applied is as follows.

That is, the light rays incident by the refraction means on the same plane are reflected while forming the same angle θ that is symmetrical with the incident angle θ with respect to the normal of the reflection surface. However, the light rays incident on the rotating reflecting surface reflect at an angle of 2Δθ when the reflecting surface is rotated by Δθ with respect to the center of the rotating body at the initial incident or reflection angle θ. In this case, the direction of the light beam is not directed to the direction of the deflection means located at the end of the swing arm.

In order to solve this problem, the refraction means located at the center of rotation of the swing arm is solved by the above-described galvanometer mirror to correct the difference between the incident angle and the reflection angle generated by the rotation. The galvano mirror applied as a means to maintain the optical axis continues to calibrate the optical axis as the swing arm rotates, and the continuous correction of the optical axis according to the rotation angle causes the delay of the access time and the servo error. .

The present invention is to improve the above problems of the swing arm method by having the optical axis of the optical pickup device in which the optical system unit is separated in the optical recording / reproducing apparatus has a predetermined refractive optical path passing through the shaft portion of the swing arm. There is a purpose.

That is, to improve the problems such as delay of access time, servo error, etc., and to improve the problem of price increase due to the addition of additional devices such as galvano mirrors.

In order to achieve the above object, the present invention vertically converts light rays incident from the separated optical system unit at a predetermined angle at the first refractive position, and the vertically refracted rays are horizontally refracted at a predetermined angle without correction of the optical axis. Since the second refraction is made so as to reach the tip of the swing arm, there is a characteristic of reaching the tip of the swing arm that is rotated without correction of the optical axis.

As a feature of the present invention, there is provided a light reflection apparatus of an optical pickup device in which an optical system unit is separated, comprising: first refractive means for causing the optical axis of the horizontally incident optical system unit to be vertically refracted at a predetermined position; And second refraction means arranged to secondary refraction along the tip of the swing arm in which the optical axis vertically refracted upward from the first refraction means is provided.

The first and second refractive means are preferably installed on the central axis of the swiss arm. Since at least two refraction means of the optical axis toward the tip of the swiss arm are provided at predetermined intervals on the outer side of the swing arm, the optical transmission path can be installed on the outer side of the swing arm. The swing arm preferably further includes a pivot bearing supported by a fixed shaft and a fixed holder. In particular, the pivot bearing forms a guide hole through which the light beam transmitted from the optical system unit passes to the side, and the fixed holder forms a light beam incident path by forming a guide hole communicating with the guide hole of the swing arm. do.

On the other hand, the second refractive means is preferably installed in the rotary holder penetrating the upper surface of the fixed holder connected to the upper portion of the swing arm in the form of a bridge.

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

3 is a schematic diagram of a swing arm type optical recording / reproducing apparatus in which the light reflecting apparatus of the present invention is implemented, and FIG. 4 is a cross-sectional view showing a light refractive path of the light reflecting apparatus of the present invention.

The light reflection device of the present invention according to the drawings is provided on the shaft portion 240 of the swing arm 200 as follows.

That is, the fixed holder 210, the central axis 220 positioned at the center of the fixed holder 210, the pivot bearing 230 installed on the central axis 220, and the pivot bearing 230 Through the shaft portion 240 of the swing arm 200, which is installed to be rotated from the outside, and the rotating holder 250 that passes through the fixed holder 210, and is connected to the shaft portion 240 of the swing arm 200 Is done.

Specifically, the fixing holder 210 is installed in the form of a cylindrical cover on the base 270 in a state in which the central shaft 220 is embedded, and the shaft portion 240 of the swing arm 200 by opening one side of the cover shape. ) Extend the tip with the cover covered.

On the upper surface of the fixed holder 210, the leg 251 of the rotary holder 250 passes to form an arc-shaped long hole 211 connected to the shaft portion 240 of the swing arm 200. The long hole 211 is extended in a range in which the lower connection portion 251 of the rotary holder 250 can be sufficiently rotated in a predetermined range.

On the other side of the cylindrical, a first guide hole 212 is formed at a predetermined position to guide the light beam scanned from the optical system unit 260 to the first refractive means 221 which will be described later. The shaft hole 213 is formed to be adhered to the shaft 220.

The central shaft 220 protrudes a predetermined length upward from the base bottom of the inner bottom center of the fixing holder 210. At a predetermined position of the central axis 220, the first refraction means 221 for refracting the light beam in a predetermined direction is inclined. At this time, the reflective surface of the first refractive means 221 is installed to face in the vertical direction in the first guide hole 212 of the fixed holder 210.

The pivot bearing 230 installs the shaft hole 231 on the central shaft 220. The pivot bearing 230 forms a second guide hole 232 for guiding the light beam scanned toward the first refraction means 221 from the light source. The second guide hole 232 coincides with the first eye hole 212 on a horizontal line.

The shaft portion 240 of the swing arm 200 rotatably centers its center on the outer circumferential surface of the pivot bearing 230. In addition, a third guide hole 242 communicating with the first guide hole 212 and the second guide hole 232 is formed on one side on a horizontal line. The upper surface of the shaft portion 240 forms a connection groove 243 connected to the lower end of the rotary holder 250 to be described later, the rotary holder 250 is placed in the shaft portion 240 in the form of a bridge. At this time, the rotation holder 250 is connected to the shaft portion 240 through the arc-shaped hole 211 of the fixed holder 210 and rotated together by a predetermined angle in accordance with the rotation of the shaft portion 240.

The rotary holder 250 is installed in the shaft portion 240 of the swing arm 200 in the form of a bridge. As described above, since the shaft portion 240 of the swing arm 200 is built in the fixed holder 210, the rotary holder 250 installed above the fixed holder 210 has a leg 251 of the fixed holder ( Passing through the arc-shaped hole 211 of the 210 is integrally connected in the connecting groove 243 of the shaft portion 240. At this time, a second refractive means 252 for refracting and reflecting the light beams passing through the first refractive means 221 at a predetermined angle is installed at the bottom of the rotating holder 250, and the refractive means 252 A predetermined light path is formed such that the broken light beam is directed toward the tip of the swing arm 200. At this time, the rotation holder 250 forms a fourth guide hole 253 through which the light ray of the second refractive means 252 passes.

In the present invention as described above, some sections on the base 270 are hollow, and the pivot bearing 230 is welded and fixed in the state in which the first refraction means 221 is installed on the central axis 220 having the side open. . On the outer circumference of the pivot bearing 230, the shaft portion 240 of the swing arm 200 is rotatable and rotatable, and the fixing holder 210 is supported on the outside thereof in the form of a cover. The rotary holder 250 is assembled to the upper side of the fixed holder 210.

At this time, in order to align the optical axis of the optical unit 260 and the side of the pivot bearing 230, the base 270 and the pivot bearing 230 are implemented as unevenness.

According to the present invention, the light beams incident horizontally from the optical system unit separated from the swing arm 200 are vertically reflected by the first refraction means 221 at a predetermined angle, and the light rays are rotated without changing the optical axis. It is made of a structure that is reflected back from the second refraction means 252 to be horizontally refracted at the angle of to reach the tip of the swing arm 200.

At this time, the light incident through the optical system unit 260 is incident on the shaft portion 240 of the swing arm 200 rotated by the first refraction means 221 to the second refraction means 252 installed above and rotated together. The optical axis change in the second refractive means 252 which is incident but is rotating does not occur.

Therefore, in the present invention, the light generated from the laser diode of the optical unit is separated from the incident light and the reflected light in the prism (PPBS) through the sensor lens, and the incident light is incident on the galvano mirror, and the reflected light passes through the collimator lens to the photodiode. In the conventional light reflecting apparatus having a light path, the problem that the optical axis correction is necessarily followed through the galvano mirror is improved.

The present invention provides an optical reflecting apparatus having a predetermined refractive optical path through which the optical axis of the optical pickup device in which the optical system unit is separated, has a predetermined optical path through the shaft portion of the swing arm, and thus the above-described access time delay and servo error due to adopting a conventional galvano mirror. There is an effect of improving the problem of price increase due to the addition of the problem and the addition of a galvano mirror.

Claims (8)

In the light reflecting device of the optical pickup device in which the optical system unit is separated, First refraction means for causing the optical axis of the horizontally incident optical system unit to be vertically refracted at a predetermined position; And And a second refraction means provided to be secondly refracted along the distal end portion of the swing arm in which the optical axis vertically refracted upward from the first refraction means is rotated. The optical reflection apparatus of the optical pickup apparatus, characterized in that to form an optical path without the optical axis correction toward the tip of the swinging arm from the separated optical system unit. The light reflection apparatus of claim 1, wherein the first and second refraction means are provided on a central axis of the swing arm. delete 3. The light reflecting apparatus of claim 2, wherein the swing arm further comprises a pivot bearing supported by a fixed shaft. 5. The light reflecting apparatus of claim 4, wherein the pivot bearing forms guide holes through which light beams transmitted from the optical system unit pass to the side surfaces. The light reflection apparatus of claim 4, further comprising a fixing holder for supporting the shaft portion of the swing arm. The light reflecting device of claim 6, wherein the fixing holder defines a guide hole communicating with the guide hole of the swing arm. The method of claim 6, The light reflection device of the optical pickup device further comprises a rotating holder having a second refractive means connected to the upper portion of the swing arm through the upper surface of the fixed holder.

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